During a speech in Denver to amp support for gun-control legislation, President Obama renewed pressure on Congress to enact stricter background checks. (Nicki Demarco/The Washington Post)

Just 10 weeks after being sworn in for a second term, President Obama sounded less than upbeat during his first campaign fundraising trip outside Washington this week.

Climate change? “The politics of this are tough,” Obama said in the airy atrium in the home of San Francisco billionaire asset manager Tom Steyer.

Gun control? “It’s going to be tougher to get better gun legislation . . . through the Senate and the House,” he acknowledged in the garden behind Levi-Strauss heir John Goldman’s home in Atherton, Calif.

Investments in scientific research? “Right now we’re constrained,” he said in the dining room of philanthropists Gordon and Ann Getty.

Obama campaigned on the notion that his reelection would help put an end to Washington gridlock. But now the reality has set in that the president appears to have little power to advance his agenda amid continued partisan polarization.

Although he continued to deliver an optimistic vision of the future, Obama also sought to manage expectations about what is possible over the next two years.

He borrowed from the Jackie Robinson biopic “42,” recently screened at the White House. In the 70 years since Robinson broke the color line in baseball, Obama said, the country has evolved into a more accepting place.

That, he suggested, is how change happens: slowly, over generations, and only after a sustained fight.

“It doesn’t happen all at once,” Obama said. “It doesn’t happen in one fell swoop. It doesn’t happen because a president gives a speech.”

The suggestion that Americans must take the long view struck a different tone from Obama’s inaugural address in January, when he emphasized that the country’s challenges were urgent.

Obama’s message aimed to temper his supporters’ impatience for action at a time when the president’s gun-control agenda appears stalled in the Senate. During a speech at a Denver police academy, Obama pleaded with people on both sides of the gun-control debate to try to find common ground. Obama’s bid to raise taxes on wealthier Americans to offset budget cuts also has been met with stiff resistance among Republicans.

At the same time, Obama’s notes of caution had another motive: to persuade supporters to open their pocketbooks again just five months after he won his final campaign. The White House has joined with congressional Democrats on a strategy to win back control of the House in 2014 and maintain their advantage in the Senate, as an insurance policy against GOP resistance to Obama’s agenda.

Although Obama said repeatedly that he still hopes to work with Republicans, he also acknowledged that his job would be easier if House Minority Leader Nancy Pelosi, who appeared with him at two of the fundraisers in San Francisco, regains the speakership.

At Steyer’s home, Obama spoke to a group of about 100 people, including many staunch backers of environmental causes. Steyer is an outspoken opponent of the Keystone XL oil sands pipeline, a project the Obama administration is considering but that environmental groups oppose.

Obama said the politics of the environment are difficult because many people are concerned about the sluggish economy, not climate change.

Standing with Pelosi behind him, Obama urged the audience to remain involved in Democratic campaigns ahead of 2014. If the party regains the House, he said, “I’m confident that not only can we deliver on this profound issue of climate change, not only can we make sure that clean energy is the norm here in America, but I also think that we can give America that sense of confidence and forward movement that’s always been our hallmark.”

Before Obama spoke, Steyer told the crowd to envision themselves as “role players” on a basketball team in which the president is the “shameless gunner” who takes the big shot. Once again, the president sought to reset expectations.

Noting with a laugh that he recently made just two of 22 shots on the White House basketball court during the Easter Egg Roll, Obama offered a different analogy.

“The way I have always thought about politics . . . is that we are a team,” he said.

Discuss this topic and other political issues in the politics discussion forums.