Here Liberal Journal reposts a Krugman column. His thesis -- the middle ground is gone.
The Liberal Journal: KrugmanKrugman gives several examples of GOP allies that now support policies that are clearly against their core interests, presumably because they believe the GOP will support their agenda better in the future -- or that the alternative is worse.
... those who cling to the belief that politics can be conducted in terms of people rather than parties — a group that also includes would-be centrist Democrats like Joe Lieberman and many members of the punditocracy — are kidding themselves.
The fact is that in 1994, the year when radical Republicans took control both of Congress and of their own party, things fell apart, and the center did not hold. Now we’re living in an age of one-letter politics, in which a politician’s partisan affiliation is almost always far more important than his or her personal beliefs. And those who refuse to recognize this reality end up being useful idiots for those, like President Bush, who have been consistently ruthless in their partisanship.
I think Krugman is correct that the overall direction of the GOP is such that no GOP candidate should ever be supported -- no matter how excellent they may be personally. This is sad, but Lincoln Chaffee will do enormous harm, regardless of his personal interests, if he keeps Bill Frist in power.
I don' t know of the middle-ground is truly gone from all aspects of US politics. There might be a place for a Clinton-style centrist president for example. Or maybe not.
It's been noted (Krugman?) that historically US politics was very partisan, and that bipartisanship may have been an artifact of post-WW II income compression. The split of US incomes into the flat middle and the ascendant extreme may have thus ended bipartisanship.