What a ridiculous question. It's not an issue of "party." It's an issue of long-term viability of the country.
If conservatives are going to retake the House, Senate and WH, in '08, it's going to take a combination of factors to defeat incumbency.
1. The GOP is going to have to nominate conservatives, not moderates or RINOs.
2. They're going to have to get the message out that the candidates are true conservatives, not moderates or RINOs, interested in reducing the size and scope of the federal government and fighting a proactive War on Terror.
3. They're going to have to have a platform, to include a true agenda of tax reform (not just cuts) and reduction in the size and scope of the federal government, that the candidates are willing to support and then enact.
4. The incumbent Dems are going to have to spend the next two years promoting their causes of liberalism.
I believe the long-term viability of the country depends on a conservative government. A vital component of achieving that in two years is for the Dems to go hog wild. If they are on their best behavior for the next two years, the moderates in the country will vote for the incumbent and Nov. 5, 2008 will feel like Nov. 8, 2006. Then we'll be dealing with multiple-term incumbents who will be harder to beat; the Dems will be better positioned if they grow their majorities and take the WH to increase social spending, make cuts to the military, grow the power of government, increase the tax burden, etc. etc. etc.
The long-term viability of the country depends on a conservative people. The government will follow.
I heard multiple exit polls asking those who had voted democrat. Most actually said they felt the dems would be more fiscally responsible than the pubbies. Most actually said they felt the dems would do a better job on controlling immigration.
The dems didn't win the election. The pubbies gave it to them. In truth, the average American, away from the major urban areas is fairly conservative.
But if the republican party wants to make promises of conservatism and not deliver, don't blame the dems.