Excellent points Frank.
This ideology and party thing is an issue here in Nebraska, with our "conservative" Democrat Senator Ben Nelson.
Nelson won election twice as governor and twice as senator because of his reputation as a conservative, rather than a far-left fringe, Democrat.
But when push comes to shove, when the bottom line is reached, a conservative Democrat helps advance the liberal Democrat agenda, because he helps make the Democrats the majority party.
"Conservative" Ben Nelson helped conservatives not at all, because on the important issues, he went with party rather than with principles.
It's noble to go with principles, but in an imperfect world, that isn't going to happen.
I've only been cursorily, casually, keeping track, but it seems to me those such as Snowe, Collins, and Brown (and earlier, congressman Christopher Shays of Connecticut, or senators Specter and Chafee) have always voted on issues of substance with the party that elected them, suborning their more-liberal principles to help conservatives.
It's noble to go with principles, but in an imperfect world that will never be perfect, it isn't going to happen.
Not being God, I have no idea how the elections of 2012 are going to turn out, and it may yet be possible it'll be a cliff-hanger, the margin of control determined by only one or two members. In which case conservatives should hail the presence of a few liberal Republicans, because they contribute to making the more-conservative party the majority party.
Or it could happen to be a Republican landslide, with more than enough conservative Republicans to make liberal Republicans less important, in which case I don't think anybody would be unhappy. But unless and until that happens, one better take what he can get.