If a RINO, (republican in name only), makes it to the general, how would he be any different than a democrat who openly admits to his liberalism? They're both liberals, but one lies about his true beliefs. I will never vote for a man whom I know is merely pretending to be a conservative. So in the case of a RINO vs a Democrat, I'll either stay home or write in Duncan Hunter. I just can't see voting for my own destruction, or for the destruciton of my country.
Fair question. The case FOR supporting RINOs is that if the R's get 50+1 then they control the Senate, which means committee assignments, and voting majorities. Without last terms R control (enabled by RINOS) the Donkeys, for instance, would probably have been able to bottle up Roberts and Alioto's Supreme Court nominations in Judiciary. Thus, no conservatives getting appointed.
There are lots of other problems with Donkeys in control, for instance Reid running the Senate with his odd rules to push amnesty. Unlikely in a R controlled Senate.
So much as we hate them it may make sense to keep a few around if we want to be in the majority.