Um... I never said that Democrats were doomed and Republicans had "smooth sailing". In fact, I stated several times that I have no idea if Dems are going to win back seats in Congress this fall or not.
I simply said that a 50% poll rate for Dems certainly does not guarantee success and if anything may indicate problems for the Dems this fall.
Polls this early before an election tend to reflect opinions on the current party in power. Period. I just personally feel that given the massive amounts of negative press that Republicans have gotten (both in the White House and Congress) over the last couple years Dems should be polling higher if they expect those numbers to carry them through an election.
I also argued that unless they present a "real platform" that includes a plan for dealing with global terror, they're going to have a very hard time keeping those numbers across a set of national elections. As election time comes nearer, voters will stop simply looking at what's going on right now and deciding if they like or don't like it, and will start looking at the alternative being presented by the Dems and decide if they like that "better". And that's a completely different decision to make.
It's easy to get lots of people to say they'd like something different then what they've got. It's a lot harder to get those same numbers of people to actually choose something different when it's a straight choice between one or the other. That's all I was pointing out. This early, voters being polled are basically answering the question "Do I think there's a better way to do this?". In 6 months, they'll be answering the question "Which solution of these two is better?". Again. Those are dramatically different questions, and poll results on one isn't going to accurately tell you how the choice will be made in the other.