I was recently watching Annie Hall and an interesting question came to mind. During a scene when splitting possessions, Alvy Singer has a bunch of buttons. Impeach Johnson, impeach Nixon, impeach Ford, and impeach Reagan.
Now the movie came out in 1977, three years before Reagan’s election in 1980. Was Reagan seen as such an eventuality in 1977 that it was considered a certainty he would become president? Was this due to his strong showing challenging Ford in the 1976 Republican primary?
I'm not an expert in 20th century American politics, or the works of Woody Allen for that matter, so it is entirely possible that my answer may be overly simplistic, but I would hazard a guess that the button to which you refer simply references Reagan's governorship of California (1967-1975). Reagan was a recognizable Hollywood figure prior to his entering politics. He was elected to the board of the Screen Actor's Guild in 1941, and was a major anti-communist figure in the blacklist era (it should be noted that Allen's The Front, about the blacklist era, was released in 1976). By the time he was elected governor, he was certainly a nationally-recognizable figure (moreso than Hugh Carey, governor of New York, for example), and, with California being the epicenter of the movie business, he was certainly a politician with whose politics Allen would have been familiar. As to whether Reagan was already considered a shoo-in for the Republican nomination when Annie Hall was being made, I will leave that for others to say.