The latest example: Republican Congressman Randy Fultgren, who couldn't even explain why we have subsidies in the first place. ThinkProgress:
CONSTITUENT: With the oil industry, we’re giving them $63 billion in oil subsidies. And you cut what, thirty one, thirty two billion? ... How about cutting that out? It’ll give you a nice tidy sum over ten years.
HULTGREN: I’m very open to looking at every subsidy that we do and questioning why we do this. And I want to know. I want to have the answers there. I just–
CONSTITUENT: But there’s no logic there. None whatsoever.
HULTGREN: Well I’ll look into that. That’s something we just talked about on the way into here.
Here's the thing: if you can't defend something, if you can't even explain why it exists, then you shouldn't have voted for it the first place. And you shouldn't keep on trying to block its repeal.