Once you cast your vote, you essentially become powerless, until the next election. Politicians have a long history of not meeting their promises. Trump will be no different than anyone else. Part of the problem is what they want to do (i.e. what they promised) is often different than what they can do. Some of this happens as a result of having to make compromises to get bills passed but a lot of it is because Congress doesn't want to do it. The executive branch doesn't control the purse strings and most things require money. This seems to be a concept that many Americans don't fully understand. Granted, politicians should use language such as "if Congress cooperates this is what I would like to do" but that doesn't play as well as "this is what I am going to do".