In 1995, the dynamics of the 1996 Presidential election changed due to the government shutdowns over GOP efforts to reform Medicare. The Republicans, with the best intentions and in trying to do the right thing, embraced a very poor strategy that enabled Bill Clinton to gain the upper hand in the 1996 election.
The same is happening in 2007, albeit it is not getting the play that the 1995 budget battle did. AJ-Strata has the details. The short version is that the Democrats were essentially banking on the troops to fail - and now that they have NOT failed, but instead have succeeded, the Dems are now in a huge pinch.
Their base is demanding an end to the war, and they have proven they can knock off those who displease them (see the 2006 primary for the U.S. Senate seat in Connecticut). However, in the 2006 general election, Joe Lieberman came back and won as an independent. In essence, the anti-war position is held by a majority of the Democratic primary eelctorate, but it is a very tough sell to the general public - and this was before things like the "General Betray Us" ad.
In essence, the Democrats are now going against the one institution that is held in high regard across a very broad spectrum of the American public. Meanwhile, the Republicans are not only sticking up for the troops and their commander, they are also following the miliary advice they are getting.
The Dems just put themselves into a hole... even though they may not realize it yet.