Wrong. That is an egregious piece of mis-reasoning. Voting for any candidate who doesn't pass the smell test only strengthens the opposition to those issues that are dearest to me. It doesn't matter what the letter is next to their name. The problem is that the parties have no clue what the people really want, and they try to give people what they THINK people want (e.g. Riordan in California). It is by ignoring the party on occasion or voting contrary to the losers that they occasionally toss us that they learn to back better candidates the next time around. Otherwise, you are just reinforcing their misconception that you liked the loser they handed you last time.
I generally vote Republican in the elections, but I WILL NOT vote for any nominal "Republican" who doesn't meet my standards. Period. By the same token, I occasionally will vote for a Democrat who for some reason is out of line with the rest of the party and actually supports the issues I hold dear to my heart. Some rural "Democrats" are more Republican than some urban "Republicans". If it quacks like a duck...
Even if your vote for that "out of line" Democrat gives the majority of the House and/or Senate to all the rest of the Democrats? The same hard core Socialist/Progressive/Liberal extremists who will chair ALL the committees, subcommittees, confirmations, budget/taxing/spendig processes, congressional agenda, etc, etc, etc, etc,.....? Is it your vote that is responsible for the Democrat control of the Senate today?