President-elect Barack Obama will enter office with a trove of political capital and a large agenda on which to spend it. But the measures that he has teed up for early action might make it difficult to fulfill two major campaign promises that have helped win him so much goodwill: to limit the role of lobbyists and to govern in an amicable spirit with the help of Republicans.

Initiatives such as the economic stimulus bill, health care reform and energy legislation, all of which Obama has promised to tackle, could place enormous stress on his relations with Republicans and involve the administration deeply with lobbyists.

The latter may be more problematic for Obama, because while few expect Capitol Hill to become the arena for an extended bipartisan love-in, Obama will probably be held to his promise to check “undue” influence from K Street.

“It’s not even an issue — you have to” work with lobbyists, said one veteran Democratic practitioner of the craft. Lobbyists will already be working Obama’s issues, he said, so “you might as well be working with them.”

Furthermore, as one Democratic lobbyist said, the Obama administration will be loaded with people who worked for former President Bill Clinton and can facilitate potential contacts with other Clintonites now on K Street.

(Giant business groups such as the U.S. Chamber of Commerce are already in touch with the Obama transition operation.)

During the campaign, Obama promised a variety of measures designed to limit the influence of lobbyists, but he did not say that they would be excluded from the government or that he would decline to work with them. Nevertheless, the sum of the proposals to fence the government off from lobbyists’ agendas adds up to a tone that is distinctly negative.

“An Obama administration will make decisions that affect the country based on what is best for the public, not what is best for lobbyists,” the campaign said in one of its published planks.

Working closely with lobbyists will at the very least put their agendas before the eyes of Obama officials.

An Obama aide said the transition is living up to the president-elect’s pledges.

“Everything we’re doing is consistent with the principles that President-elect Obama laid out during the campaign,” spokesman Nick Shapiro said. “We are operating under the farthest-reaching ethics policy in history.”

The transition has laid out a set of rules that are expected to form the template for the administration’s policies toward K Street, including a gift ban, a stipulation that lobbyists cannot contribute financially to the transition and a requirement that lobbyists working on the transition wait 12 months before lobbying the administration on matters on which they worked.

Obama has made clear that the first job of his administration will be righting the economy. He is widely expected to back what is likely to be a mammoth stimulus bill loaded with the type of spending measures that Republicans hate and lobbyists love.

With Congress prepared to work on the bill in January, Obama may find himself allying with lobbyists who want to pass it while angering Republicans balking at the price tag — all before he even takes office.

Even GOP allies in the business lobby could find themselves helping Obama if the mix of projects is right — particularly if business tax breaks are part of the recipe.

“We have a list of items” for the stimulus, said Dan Danner, chief lobbyist for the National Federation of Independent Business. Danner outlined a series of tax benefits led by changes to the rules governing the depreciation of new purchases.

Such tax provisions could be used to court the support of Republicans. But the GOP, while saying it hopes to work with Obama, has already signaled that the new president will be in for a fight if too much money goes for asphalt and other such items.

“Democrats can’t seem to stop trying to outbid each other — with the taxpayers’ money,” House Minority Leader John Boehner (R-Ohio) said in a recent statement.

A Boehner spokesman said Republicans intend to “reach back” if Obama “extends his hand to us.” But he warned: “We agree with the American people that more Washington spending is not the answer.”

Obama’s sweeping health care initiatives, with their proposals for mandatory coverage, could provide a serious test for his determination to get along with the GOP. Republicans say many in the Conference are deeply concerned that Obama’s plans will end up driving people into a public health care option without doing enough to preserve the private system.

And lobbyists will be deeply involved in the fight, whether they represent high-tech businesses getting behind Obama’s effort to invest in new health care technology systems or insurers who don’t necessarily like Obama’s ideas on expanding coverage but want to steer a process to limit damage or even gain new enrollees.

“They’ll be better able to manage it if they’re in the tent than if they’re not,” said one lobbyist who has worked the health care beat.

The upcoming campaign to craft energy legislation presents one of the best opportunities for generating kumbaya moments featuring Obama and the GOP.

Republicans generally support efforts espoused by Obama to spur the development of alternative fuel technologies.

Nevertheless, while Obama’s opponent in the presidential campaign, Sen. John McCain (R-Ariz.), backed mandates for reducing greenhouse gas emissions, many Republicans are wary that a cap-and-trade plan could harm the economy.

The energy effort will also present Obama with an endless list of potential K Street allies lined up to promote their special brand of clean energy — from ethanol and biodiesel to clean coal, electricity, hydrogen and natural gas and anything else that can be found to propel a vehicle forward.