Adding to the always insightful Steve Benen, there is almost no ideological range in the Republican Party. Name me a Republican who is willing to filibuster a judge because the judge wants to overturn Roe v. Wade or a Republican who wants to raise marginal income tax rates. You would never see a pro-choice rump rise up in the Republican House to mirror the Stupak bloc. Only a small handful of Republicans have ever voted against war supplementals. There are less than five Republican members in either chamber of Congress who deviate in any meaningful way from conservative orthodoxy. So, it is painless to take the most conservative positions on issues. But there is an enormous ideological divide between Ben Nelson and Bernie Sanders or the Congressional Black Caucus and the Blue Dogs. Maxine Waters and Bobby Bright barely inhabit the same planet. How would progressive (or hard left) Democrats even begin to purge the party of moderates? We are completely dependent on them for our majorities. And, as much as we chafe at this reality, we at least have the common sense to understand it (most of us, anyway).