I'm not aware of any politician who delivers on his/her promises, either. Obama, if you recall, promised to investigate the previous administration and how we got into Iraq. He promised strict regulations and investigations of the financial sector for crashing the economy. He promised to close Guantanamo. He promised more progressive tax reform. None of those happened, or happened in such a weak way that it wasn't much of a difference. Despite this, I think he was a good President. He got us out of a foreign policy hole, reformed health care (not enough, but in the right direction), and got our economy going again. I think we need about a year to make an assessment of any President, so I'm waiting at least that long.
Now, Trump could change that. If he (say) decides on a whim to nuke North Korea or Iran, that would be very bad. If he takes some action that crashes the economy, that would be very bad. And some things have already bothered me. I think there does seem to be some substance to the Russia connection. The Comey firing is pretty shady. Trump's manner is odd, to say the least. I suspect that his policies are going to lead to serious trouble, but again, I think we just have to wait and see. If I'm wrong about Trump's policies leading to bad consequences, then great! That means our country does well, or at least not badly. If I'm right, I hope that folks on the conservative side of the spectrum do some honest examination of their beliefs, and in any case, it'll mean swing voters will tend to move left.