Pols like Jeff Van Drew who prioritize political fortunes over policy or duty to country haven't typically been rewarded for that cowardice. No one who paid attention in those hearings or to evidence could credibly conclude Trump didn't do the grievous things he's accused of.
Dems voting against impeachment probably thinks it will help them keep their seats in Congress in more conservative districts. Democrats like former Rep. Gene Taylor (D-MS) thought that when voting against the ACA. He & others still lost their seats in the 2010 Tea Party wave.
Ex-GOP Rep. @JustinAmash concluded that Trump should be impeached after reading the Mueller report; he didn't even need the Ukraine story to get there. For that, he had to leave his party & faces tough prospects in his conservative district. He hasn't backed down.
*think
