The Candidate (1972) on Netflix

Handsome Bill McKay is not his father's son, his father being former California Governor, John J. McKay. An idealistic civil rights lawyer, Bill believes the political process is all style over substance, and thus he can accomplish more for the people, many of those disenfranchised, in his role as lawyer than politician. For the upcoming midterm election, Bill is approached by strategist Marvin Lucas to contest the Democratic nomination for the California senate seat, the actual election against wildly popular Republican incumbent, Crocker Jarmon. Marvin is able to sell Bill, with his supportive wife Nancy at his side, on the idea as he can easily win the nomination, but has no chance of winning the actual election against Jarmon and thus he can freely speak his mind to the California electorate. Bill's biggest condition is that his father not be involved at all, Bill not wanting his father's legacy to overshadow any of his own messages. Unfortunately for Bill, McKay Sr. may influence Bill's campaign whether or not he is directly involved. What Bill did not account for is that he has to make a credible showing or else his own reputation as a human being may be in jeopardy. So as the polls continually change for the good or bad for Bill, he may buckle under the pressure to become what he didn't want to be in the first place. His entire life, including his marriage, may also be totally taken over by the campaign process until election day.