How to avoid the GOP's mistakes during the Bush years?

The Atlantic's Marc Ambinder makes the following observation:

From day one of his administration, the left has held Barack Obama's feet to the fire way more than the right ever did to George W. Bush -- at least until Bush's nomination of Harriet Meirs to the Supreme Court. Put another way: the diversity of opinion about Obama and his presidency among activist Dems far exceeds early Bush-era diversity of opinion among activist GOPers.

Is there any doubt that this is accurate?  I...