As I type this, Keith Olbermann is sputtering in fury, trying ever-so-desperately to spin Martha Coakley’s loss to Scott Brown in Massachusetts, while issuing any insult he can possibly think of in the direction of Scott Brown, and the Republicans. But despite Olbermann’s efforts to complicate the analysis–and despite his inability to understand what he is trying to analyze–the explanation for the Scott Brown win and the Martha Coakley loss is quite simple.

For one thing, candidates matter. Scott Brown was a great one, and Martha Coakley was a terrible one. Brown smartly channeled discontent with the Obama/Democratic agenda, and used it to propel his campaign at Coakley’s expense. He successfully got independents on his bandwagon, thus helping him overcome the Democratic registration advantage. His “it’s the people’s seat” comment in the debate with Martha Coakley was instrumental in helping him consolidate populist support, and he ran a campaign that was significantly more vigorous than the one run by Martha Coakley and the Democrats.

Speaking of Coakley, her decision to take a vacation from the campaign trail, while Brown got to define himself and her for the benefit of the voters, has to rank as one of the most disastrous ideas ever hatched in the midst of a campaign. Equally disastrous, of course, was her decision to take potshots at Scott Brown’s efforts to campaign at outdoor hockey games, her stated belief that there are no terrorists in Afghanistan, and her revelation that she thought Red Sox legend Curt Schilling was a Yankees player. It takes a startling amount of incompetence for a Massachusetts Democrat to lose a Senate seat held by Ted Kennedy, and by JFK himself, but Martha Coakley exhibited that incompetence in spades.

But it cannot be forgotten that ideology played a role in Scott Brown’s win as well. There was no disguising the fact that validation of the Obama/Democratic agenda was on the line in the Senate race–especially the portion of the agenda dealing with health care reform. No one doubted that Martha Coakley would go to Washington and vote in favor of health care reform, if she were elected. And no one doubted that Scott Brown would go to Washington and sink health care reform as Massachusetts’s next Senator. In bluer-than-blue Massachusetts, Brown’s approach was validated over Coakley’s. Whatever the amount of incompetence and bumbling Coakley exhibited, Massachusetts’s rejection of her–and Barack Obama’s–domestic policy vision constitutes an ideological, philosophical defeat for the Democratic party that transcends campaign competence, or the lack thereof.

Could the Democrats have won if they had run a competent campaign? Possibly. But it likely would have been a close victory, and Democrats still would have been startled by what would have been a significant protest against the Obama/Democratic agenda. Whatever one might say about the quality of the Coakley and Brown campaigns, the conclusion that the voters delivered a negative judgment on the Democratic platform is inescapable.

And now, Republicans have a roadmap to further electoral wins, one provided to them by Brown and by Bob McDonnell, the newly elected Governor of Virginia: Focus on economic issues, run positive and appealing candidates with positive and appealing campaigns, and don’t be afraid to directly take on the White House and the Democratic establishment.

If this approach can pay dividends in Massachusetts, it can pay dividends elsewhere as well–including conservative House districts represented by Blue Dog Democrats.