The national Republican Party this week sets out on a quest to label President Obama a “hypocrite,” seeking to contrast his 2008 message of hope and results with his 2012 campaign’s already more combative and negative tone.

It begins this week with a new web video from the Republican National Committee titled “From Hope to Hypocrisy” and promises to be a defining GOP message for the now-starting general election campaign.

So does a president who spent much of the 2008 campaign talking about a positive vision for the country pay a price for going negative?

Ask basically any campaign consultant, and the response is unanimous: Negative campaigning, nine times out of 10, works. Even if it means the candidate who goes negative pays a price, that price generally pales in comparison to the benefits in defining his or her opponent.

With Obama, though, we have more of a special case. This is the guy, after all, who eight years ago created his political brand with a stemwinder of a Democratic National Convention speech decrying the divisiveness of politics, and who four years ago ran a campaign defined by a positive vision of “hope” and “change.”

Today, Obama’s campaign is very much playing the usual political game of divide and conquer. It has gone with a populist message that is already being used to cast Mitt Romney as the candidate of the elites. The campaign is also doing its best to make that case that the Republican Party is anti-woman, attempting to turn half the electorate on its opponent.

This new approach was epitomized by Obama’s speech last week to the Associated Press, in which he accused the GOP budget of being a “Trojan horse” and “thinly veiled Social Darwinism,” and later in the week when the Democratic establishment lashed out at RNC Chairman Reince Priebus for making an analogy about women that involved caterpillars.

Both are sound political strategies, to be sure, but next to the Obama campaign’s previous, more positive slogans, the stark change in tone is notable.

“In 2008, Candidate Obama promised he was different,” says the RNC’s new web video. “Four years later, we know it was all an act.”

RNC spokesman Sean Spicer said the theme will be key to the campaign going forward, and that Obama will pay a price for both not delivering on his promises and for casting himself as the anti-politician.

“Last time, he sort of threaded the needle, talking a lot of about hope; one flank was hope and change, while the other was attacking John McCain,” Spicer said. “This time, he’s abandoned that one flank.”

At the same time, four years is a long time in politics, and this isn’t the first time Obama has shifted tactics. In fact, his first term has been a gradual acknowledgment of the political realities of the day, most recently when his campaign said it would embrace super PACs, which Obama previously derided as harmful to democracy.

It became clear long ago, in other words, that Obama, like nearly everyone in politics, has to play politics.

“I’ve rarely found that attacking a candidate — regardless of party or of ethos — on the process of campaigning has been successful,” said Democratic pollster Fred Yang. “At its core, the RNC campaign is saying that Barack Obama is a politician. That’s not exactly a news flash.”

Another Democratic aide, granted anonymity to speak candidly about strategy, said the GOP’s strategy runs against its track record of standing resolutely against the president on most major legislation. In other words: Who is the GOP to accuse the president of a lack of results and political gamesmanship?

“There are plenty of examples out there for Obama to use on how the Congress did not work with him in some cases on efforts to be more inclusive on policy,” the aide said.

Indeed, that seems to be the Obama campaign’s trump card against the new GOP strategy. It goes something like this: Yes, the president is political, but the opposition has left him no choice.

And at least for now, the Republican Party is held in very low regard. The most recent CNN/Opinion Research poll showed just 35 percent of Americans had a favorable opinion of the GOP, compared to 58 percent who had an unfavorable one. Democrats, by contrast, were viewed favorably by 48 percent and unfavorably by 45 percent.

But when you’re struggling, one of the best things you can do is make sure the opposition is struggling too. That’s what the RNC’s new web video is about — casting doubt about the profile Obama has built for himself and making the case that he’s just another politician.

If it works, we will see the Democratic brand (and Obama’s) start to suffer as well.