Washington, for the most part, is driven by three distinct forces: money, power and — while it sometimes becomes subservient to the first two — principle. These forces are immutable and eternal, perhaps in almost any seat of power. If you want to understand why President Barack Obama’s outreach campaign toward the Republicans is foundering over his first legislative initiative, the stimulus, it is because his effort is already colliding with all three.

Obama is now switching tracks, choosing to bash the GOP for seeking to encumber the stimulus with “failed” policies of the past and a reliance on tax cuts as a panacea. Obama has recognized that with Republicans reluctant to play much ball in either the Senate or the House, he needs to add a little old-fashioned Washington partisanship to his repertoire of togetherness.

GOP sources up and down Capitol Hill insist that while they are deeply appreciative of Obama’s outreach and believe that the president is sincere, they cannot sign on to legislation like the stimulus bill — which many find to be an expensive vehicle for Democratic priorities — just because Obama is being nice.

“For Members of Congress, they have to look at the bill and make their evaluation based on what they see,” said one GOP leadership aide. Republicans are particularly rankled, ironically, by Obama and other Democrats’ suggestions that the GOP should be pleased with the level of tax cuts in the legislation. Republican aides say they get no kick out of tax reductions for those who are not even paying federal income taxes.

But some GOP strategists also point to a darker game Republicans must play as they confront the Obama outreach. Republicans don’t get out of bed every morning thinking about how they can please the president. They arise to seize power in 2010 — or by 2012 at the latest — back from the Democrats in the House and the Senate. And they can’t do this if they are in bed with Obama.

“Republicans must have a goal of demonstrating that there is a difference between the parties,” said one veteran GOP strategist. “Over the last four years, the differences have been muddled or lost. In the 2008 election, there was no difference between the parties — certainly not on spending.”

Republican activist Grover Norquist, president of Americans for Tax Reform, pointed to two historical examples to describe separate roads Republicans could follow: President George H.W. Bush’s effort to compromise with Democrats by abandoning his “No New Taxes” pledge, and Republicans in 1994 whose differences with President Bill Clinton were enshrined in the “Contract with America.” The former was defeated for re-election, the latter swept into power.

Similarly, Republicans will need their own agenda and an image as a departure from the Democrats if they want to have something to sell when they go trolling for money.

One longtime strategist said that while wealthy donors want a deal on the stimulus since it will help their portfolios, the conservative base deeply opposes Obama and wants more raw meat to chew on and less cooperation.

The GOP needs both groups, he said, but if he had to choose it would be the base. If Republican leaders want to imitate the type of massive grass-roots fundraising success Obama had, they will need to oppose Obama and generate policy differences that make average people want to part with increasingly scarce resources.

But opposing Obama, whether because of principle or politics, has to be done with great care, GOP strategists suggested.

“I don’t think even GOP base voters want Congress to be obstructionist,” veteran Republican strategist Gary Andres said. “If at the end of the day, they can’t agree because of philosophical differences, then it’s OK.”

Republican strategists emphasized that the GOP must offer positive alternatives to gin up the base and not anger voters.

“Being Obama-lite doesn’t get you anything,” one strategist said.

Norquist noted that “10 percent less” of a Democratic proposal is still a Democratic proposal. “Republicans have to offer real, credible, grown-up alternatives,” he said.

The GOP should always be “open and reasonable” to Obama’s gestures, according to Norquist, and then develop a list of ideas that were ultimately rejected, whether by him or Democrats in Congress.

But Obama’s strategy of trying to bring Republicans in may nevertheless yield benefits for the president, according to GOP sources. This is because Obama is working the one angle that can mitigate and even at times defeat the three forces: relationships. People are still susceptible to the friend bug in Washington, and it can sometimes overrule self-interest.

“Even if it doesn’t get Republican votes now, it could get some on another issue,” Andres said of Obama’s efforts on the stimulus.

A senior House Republican aide noted one fringe benefit of Obama’s outreach to Republicans: It ends up being an effort to move the legislation in a direction Democratic leaders might not want.

“It drives the Democrats nuts,” he said, just like it did the GOP on the rare occasions when former President George W. Bush went around them to Democrats.