Political Parties don’t vote.
People do.
Those people are answerable to the folks back home who voted for them. If a member of Congress votes the way their party leaders want them to they should be held accountable when the next election comes around. We all should remember that.
It’s probably a good idea to put a piece of paper on the refrigerator to remind yourself when your member of Congress votes in a way you like or dislike.
It will help you vote next time.