One look at the RCP head-to-head matches for Obama vs. McCain, Clinton vs. McCain show falling support for the Dems. The Obama margin which used to be near 10% is now down to a tie at around 1%. Clinton had lost her edge two months ago and is also at a statistical tie with McCain. Neither situation is good for the Dems who need to be at least 5% ahead going into the election to have a prayer (which has been the historical gap between GOP and Dem presidential candidates which turn out to be near ties).

What has been the driving force behind this shift? Clearly the battle between Clinton and Obama has been the big news for the weeks this drop has occurred, so it is safe to assume that the marks Clinton is making against Obama is basically dragging him down. And as Obama loses his edge against McCain he loses one of his strongest arguments against Clinton – though he still has the edge in votes and delegates.

This is all great news for McCain who can let the Dems scar each other up while he goes out and raises money and puts his national organization into place. The Dems chances of winning the presidency have always been low in my opinion. America’s fondness for divided government (they don’t really trust either party unfettered) means the Dems clear leads in the House and Senate would push many voters to look for a check and balance in the White House.

But there is another factor – coat tails. It may end up, once all the infighting has done its damage – that the Dems hopes of increasing their margins in the House and Senate will be muted as the comparison between the more natural conservative trend of the American people starts butting up against the Dems more liberal and unpopular positions. Once the Obama phenomena is torn apart, and their is no more fanciful ‘hope’ about mythical ‘change’, the reality of the two parties actual positions will start to modulate the American people’s expectations. Pragmatism is McCain’s strongest strength – which will replace the Obama myth with a centrist reality that we can move from the fringes towards the middle and America looking more at common ground than being obsessed with the differences, which politics doesn’t usually resolve.

Update: A new Wall Street Journal poll bears out the same sinking trend for the Dems.

A couple findings in the new poll capture how conflicted Americans are. By a 13-point margin, 50% to 37%, registered voters say they would prefer a Democrat to be elected president. When asked to choose specifically between Arizona Sen. McCain and either Democrat, the results in each case are a statistical tie. (Poll results5)

Illinois Sen. Obama edges Sen. McCain by 47% to 44%, while Sen. Clinton, of New York, beats the Republican by a near-identical 47% to 45%. The poll, which surveyed 1,012 registered voters March 7-10, has a margin of error of 3.1 percentage points.

…

Of 10 attributes measured in the poll, Sen. McCain scored highest for “being knowledgeable and experienced enough to handle the presidency.” Nearly two-thirds of voters agreed — up 12 points from December, when both parties’ nominating races were getting under way. His next-highest ratings, from 61%, were for strong leadership and for readiness to be commander in chief.

And the bloodletting on the left is just starting!