If Nixon hadn't resigned, they probably would have managed to impeach him, even though he basically did nothing wrong.
But since Watergate the press has steadily lost credibility, until a news reporter is about as respected as a tort lawyer.
They have tried again and again to work up a propaganda campaign to destroy Bush. It has undoubtedly diminished his popularity, but it has not succeeded in eliminating his majority support. The more desperate they get, they less power they have. I dare say that Karl Rove and the rest of the Bush team are fully prepared for the worst they can come up with.
Some wacko Democrats tried to introduce impeachment article against President Reagan after the invasion of Grenada and again after the revelations of Iran-Contra. It's as predictable as the sun rising and setting.