WASHINGTON — Rep. Paul Ryan has a message for fellow Republicans: Let’s stick together and carefully pick our fights with President Barack Obama.

In a speech Saturday to conservatives, the Wisconsin congressman and 2012 vice presidential nominee outlined a pragmatic approach for dealing with a second Obama administration. Saying that Obama would attempt to divide Republicans, Ryan urged them to avoid internal squabbles.

“We can’t get rattled. We won’t play the villain in his morality plays. We have to stay united,” Ryan said at the National Review Institute’s weekend conference on the future of conservatism. “We have to show that if given the chance, we can govern. We have better ideas.”

The GOP is reeling from back-to-back presidential defeats and trying to determine whether to oppose Obama at every turn or shape his proposals with conservative principles.

How the party rebounds was a major theme of the three-day meeting of conservative activists, a dominant voice in the GOP. A similar theme dominated the Republican National Committee’s winter meeting, which ended Friday in Charlotte, N.C.

With a surging minority population altering the electorate, Republican leaders have discussed the need to attract more women and Hispanics while at the same time standing firm on the values that unite conservatives. Republicans said despite the losses, the party could return to power by projecting optimism and attracting new voters with a message of economic opportunity.

Wisconsin Gov. Scott Walker, a star among conservatives after surviving a union-led campaign to recall him from office, said government needed “brown-bag common sense,” a reference to his frugal practice of packing his own lunch of ham-and-cheese sandwiches every day. Qualities like optimism, staying relevant to voters and showing courage in tackling big problems would be rewarded at the voting booth, he said.

“We’ve got to learn to be more optimistic. We’ve got to learn to give a viable alternative to the voters,” Walker said.

Sen. Ted Cruz of Texas said Republicans needed to use upcoming fights over the budget and the deficit as “leverage points” to tame long-term spending and debt. Projecting an upbeat outlook for the party, he said Obama’s policies would drive many voters to Republicans just as many Americans turned to Ronald Reagan after the economic turmoil of the late 1970s.

“We’re on the verge of a rebirth of conservativism,” Cruz said.

Looking ahead, Ryan rejected the notion that Republicans were “in the wilderness,” noting that the party controls the House and most statehouses. But he said Obama’s victory over Romney meant that Republicans would need to recalibrate their approach to deal with the new political realities.

“If we want to promote conservatism, we’ll need to use every tool at our disposal,” Ryan said. “Sometimes, we will have to reject the president’s proposals — that time may come more than once. And sometimes we’ll have to make them better.” He said Republicans should have two main goals for the next four years, namely “to mitigate bad policies” and “to advance good policy wherever we can.”

Ryan acknowledged that “we all didn’t see eye to eye” on the recent “fiscal cliff” vote to deal with a combination of spending cuts and higher taxes that were set to take effect at the start of the year. He defended his support for the bill, saying it was the only way to avoid sweeping tax increases and prevent the economy from going into a free-fall.

As chairman of the House Budget Committee, Ryan said Republicans needed to guard against a debt crisis for the country that would undermine the economy. He said he would promote changes to Medicare and Medicaid and would propose a budget “that will balance and pay down the debt.”

But November’s election results still linger. Ryan said he was “disappointed” by the outcome, saying he was “looking forward to taking on the big challenges” while living at the vice president’s residence. “My kids were looking forward to having a pool,” he joked.