delivered the opinion of the Court.
In 1949 Mrs. Doris Walker was discharged from her job at Cutter Laboratories, a manufacturer of pharmaceutical and biological products, on the claimed grounds that she was an active member of the Communist Party and had falsified her application for employment there.1 *294Petitioner, Bio-Lab' Union of Local 225, United Office & Professional Workers of America, sought reinstatement for Mrs. Walker before an Arbitration Board pursuant to a valid collective-bargaining agreement which author*295ized discharge for “just cause” only. The Board determined that she had been discharged for union activity and, by a vote of 2 to 1, ordered her reinstatement. The Superior Court of San Francisco County confirmed the award and ordered it enforced. On appeal, the District Court of Appeal affirmed. The Supreme Court of California, however, reversed. 43 Cal. 2d 788, 278 P. 2d 905. Petitioners contend that the decision and opinion below violate constitutional principles embraced in the Equal Protection and Due Process Clauses of the Fourteenth Amendment. We granted certiorari, 350 U. S. 816.
*296Before Mrs. Walker applied for a job at the Cutter plant, she had graduated from law school, worked for three years as an attorney for the Office of Price Administration and in private practice, and had been discharged for union activity from jobs in three different canneries. All of these facts, she readily admitted to the Board, were concealed or misrepresented by her in the Cutter employment application in 1946. In addition, she admitted that she had falsely stated that she had been employed as a file clerk in 1939 by one John Trippe, attorney. She told the Board that no such person or employment had existed. The character references she listed had been warned by her of the omissions and falsifications in her application and at her request they did not disclose her true background to Cutter. These falsifications and omissions were not discovered until after she had been employed as a label clerk by the Cutter plant and the “probationary period” had expired.
The Arbitration Board found that Mrs. Walker had played an active role in union activities at the Cutter plant. In 1947 she became a shop chairman and a member of the executive board of the Local. The following year she was elected chief shop steward, and her activities were extended to all manufacturing departments of the Laboratory. She became president of the Local in the spring of 1949, and was holding that office at the time of her discharge. The Board also found that Mrs. Walker was a member of the Communist Party during the period of her employment. Cutter had investigated her in 1947 and 1949 and had discovered evidence of Communist Party membership and also that she had falsified her employment application. The Board’s finding of Communist Party membership was based on evidence uncovered in the Cutter investigations plus Mrs. Walker’s *297refusal to answer questions relating to membership and the Union’s offer to stipulate that the company could reasonably have concluded that she was a Communist.2
The Board took the “view of the record” that Cutter honestly believed that Mrs. Walker had falsified her application and was a member of the Party. But it held that, “while an employer may have sufficient grounds for a discharge,” he “should not be entitled to carry mutually known grounds for discharge in his hip pocket indefinitely for future convenient use.” It found Cutter’s grounds to be “stale” and concluded that Mrs. Walker was unjustly discharged and that this action of Cutter “interfered with, restrained and coerced an employee because of participation as an officer and negotiator on behalf of the Union in a wage negotiation.”
The majority opinion of the Supreme Court of California contains broad statements to the effect that specific performance of the arbitration award would violate the public policy of the State. Petitioner’s constitutional arguments are based on the belief that these statements establish the ground on which the judgment below was based, and that therefore the decision below not only establishes a conclusive presumption of advocacy of violence from the mere fact of membership in the Communist Party, but renders unenforceable substantially all contracts entered into by members of the Party.
This Court, however, reviews judgments, not statements in opinions. Herb v. Pitcairn, 324 U. S. 117, 125-126; Morrison v. Watson, 154 U. S. 111, 115. See also *298Williams v. Norris, 12 Wheat. 117, 118, 120. At times, the atmosphere in which an opinion is written may become so surcharged that unnecessarily broad statements are made. In such a case, it is our duty to look beyond the broad sweep of the language and determine for ourselves precisely the ground on which the judgment rests. This means no more than that we should not pass on federal questions discussed in the opinion where it appears that the judgment rests on adequate state grounds. Herb v. Pitcairn, supra; Williams v. Kaiser, 323 U. S. 471, 477.
It is significant that the Supreme Court of California did not limit itself to a discussion of the application of the California public policy. It also subjected the findings of the Arbitration Board to a scrutinizing review. Of course, the scope of review of such findings under the California Arbitration Act is a matter exclusively for the courts of that State, and is not our concern. Allen-Bradley Local v. Labor Board, 315 U. S. 740, 747.
First, the court determined that, since Mrs. Walker was a continuing member of the Communist Party, the doctrine of waiver could not be applied to this ground for discharge. The court noted that Mrs. Walker had remained a member of the Party “on an active and devoted basis even at the time of the board hearings.”3 43 Cal. 2d, at 807, 278 P. 2d, at 916.
Second, it is clear that the individual parties might have agreed that the circumstance of Communist Party membership would constitute “just cause” under the contract, and no federal question would thereby be raised. It is implicit in the Arbitration Board’s opinion that this *299was a reasonable construction of the contract, but since it applied a doctrine of waiver, no explicit findings on this point were made. But, as we read the opinion of the Supreme Court of California, after concluding that waiver could not be applied to the facts of this case, it decided that the “just cause” provision of the contract permitted discharge on the ground of Communist Party membership, and that Mrs. Walker was discharged on that ground. The court stated, “The contract between Cutter Laboratories and the Bio-Lab Union cannot be construed, and will not be enforced, to protect activities by a Communist on behalf of her party whether in the guise of unionism or otherwise.” 43 Cal. 2d, at 809, 278 P. 2d, at 917. At another point, the court noted that “an entirely adequate ground [Party membership] for refusing to employ her (whether by original refusal to hire or by discharge) was a continuing one which was available to the employer at any time during its existence.” 43 Cal. 2d, at 807, 278 P. 2d, at 916. In this connection, it might also be noted that the court below discussed the history of the clause in the contract which prohibited discrimination “because of race, color, creed, national origin, religious belief, or Union affiliation.” At one time the word “political” as well as “religious belief” was included in the provision, but, by negotiation, it was deleted.
We believe that the Supreme Court of California construed the term “just cause” to embrace membership in the Communist Party, and refused to apply a doctrine of waiver. As such, the decision involves only California’s construction of a local contract under local law, and therefore no substantial federal question is presented. Moreover, even if the State Court’s opinion be considered ambiguous, we should choose the interpretation which does not face us with a constitutional question. See *300Stembridge v. Georgia, 343 U. S. 541, 547, and cases cited. Cf. United States v. Rumely, 345 U. S. 41. It follows that the writ must be
Dismissed.
Mr. Justice Reed would affirm the judgment below.At the time of discharge a written notice was read to Mrs. Walker by a company official in the presence of another company official, an assistant shop steward of the union and a company stenographer. The notice read as follows:
“Mrs. Walker:
“As you are aware, the company has known for some time that when you applied for work with Cutter Laboratories on October 4, 1946, you made a number of false representations on your ‘Application for Employment.’
“As we know now, you falsified the statement of your education so as to conceal the fact that you had completed a law school course at the University of California’s School of Jurisprudence at Berkeley in May, 1942. You concealed the facts that you received the degree of Bachelor of Laws in May, 1942, and that you were admitted to the State Bar of California on December 8, 1942. You concealed that since that date you have at all times been admitted and entitled to practice as an attorney before all of the Courts of California.
“We know now that by falsification of the name of a previous *294employer, you concealed the fact that from June, 1942 to February, 1944 you were employed by the Federal Government’s Office of Price Administration, including employment as an Enforcement Attorney at a salary of about $3,200.00 a year.
"We know now that you deliberately concealed from us that from February 1944 to December, 1945 you were employed as an attorney by Gladstein, Grossman, Sawyer and Edises, a well-known firm of lawyers specializing in labor cases.
"You know that a few weeks ago the 'Labor Herald,’ the official CIO newspaper, stated that the National Labor Relations Board had sustained a cannery firm that had discharged you for refusing to answer whether or not you were a Communist.
“We have checked the records. We know now that you deliberately concealed that in 1946, just before you applied for work here, you were employed by a series of canneries and had been discharged by them.
“Ordinarily, an employee of the Company would be discharged immediately for falsifying material facts on an ‘Application for Employment.’ Because you were an officer of the Union we kept you on the pay roll rather than open ourselves to a charge of persecuting a union officer. We have given your case careful consideration because we know very well that no matter how strong the case against you there will be a claim of discrimination because of union activities.
“Because no employer wants to become involved in a dispute of that kind we have been patient and deliberate in our consideration of your misconduct.
“On October 1, 1948, when you testified under oath before a Trial Examiner of the National Labor Relations Board, you refused to answer the question as to whether or not you were a member of the Communist Party.
“You refused to answer under oath the question as to whether or not you were or had been a member of the Federal Workers’ Branch No. 3 of the Communist Party.
“You refused to testify under oath whether or not you were or had been a member of the South Side Professional Club of the Communist Party.
“We are convinced now, that you were and still are a member of *295the Communist Party, that you were a member of the Federal Workers’ Branch No. 3 of the Communist Party, and that you were a member of the South Side Professional Club of the Communist Party.
“Our recent investigation of your past record has uncovered previously unknown conduct that goes far beyond a mere concealment of material facts. We have Just completed a thorough investigation and have a full report upon your past activities. We realize now the importance of the facts that you concealed from us. We realize the full implications of your falsification and misrepresentations. A follow-up and investigation of the ‘Labor Heralds’ recent revelations has uncovered a situation far more grave than we expected.
“We are convinced now that for a number of years, you have been and still are a member of the Communist Party. We are convinced beyond any question that for a number of years you have participated actively in the Communist Party’s activities.
“The nature of our company’s business requires more than the usual precaution against sabotage and subversion. Upon a disclosure that any employee is a member of the Communist Party, or has participated in other subversive or revolutionary activity, we conceive it to be the responsibility of management to take action.
“Confronted with such a situation, any inclination to be lenient or to grant a union official special consideration is out. In the face of your record there is no alternative open to us except to terminate your services at once. Accordingly, you are notified now that you are discharged for the causes mentioned. You will be paid the full amount due to you promptly.”
Since the Board was authorized to inquire into the reasons for her discharge and the questions were, as it ruled, relevant to the issue, it could draw such inferences as were warranted. In this respect the case is unlike Slochower v. Board of Education, 350 U. S. 551.
While the court also spoke of its public policy in reaching this conclusion, its reasoning outlined above amply supports its conclusion.