Related Questions on Metaculus:

So far, the United States has had three presidents out of 44 total be impeached: Andrew Johnson in 1868, Bill Clinton in 1998, and Donald Trump, the current president, in 2019. Richard Nixon in 1974 resigned when it seemed likely that he would be impeached and convicted.

One notable feature of this list of dates is that the last two impeachments were relatively close together relative to the span of US history. As such, it seems possible that we live in a time where presidents are more likely to be impeached.