WASHINGTON — Republicans have officially added a new weapon to their political arsenal aimed at President Barack Obama’s re-election prospects.

During the first day of this year’s Conservative Political Action Conference, more than half of the speakers denounced Obama’s recent decision to require all religious institutions to include contraceptives in their employees’ health care plans by next summer.

American Conservative Union Chairman Al Cardenas foreshadowed the conference motif in an appearance on MSNBC’s “Morning Joe” on Thursday morning.

“People are coming here angrier than I’ve seen in a long time,” he said on the talk show. “And it’s not just social conservatives — anytime that big government imposes its will against the average American… it fires all conservatives up.”

Cardenas’ organization hosts the annual gathering of conservatives at the Marriott Washington Wardman Park hotel. This year, it runs through Saturday, with GOP presidential hopefuls Rick Santorum, Mitt Romney and Newt Gingrich stopping by Friday.

But even convention-floor buzz surrounding the Republican primary seemed muted compared with the birth control debate.

In a midday speech, former GOP presidential candidate and Texas Gov. Rick Perry said Obama is “assaulting the Catholic faith,” later calling the president’s intentions a “war on faith.”

Obama announced late last month that religion-affiliated groups such as universities and hospitals must provide birth control as part of the health insurance they offer their workers. The president’s order conflicts with Catholic beliefs that disapprove of most forms of contraception.

Obama is giving affected institutions until August 2013 to comply.

The topic’s persistence Thursday all but ensured Republicans will continuing using it as a political sticking point heading into this year’s general election.

The most direct criticism came from Senate Minority Leader Mitch McConnell, who called the administration’s move “more than just a violation of conscience.”

“At a place like Notre Dame, freedom of religion will now cost about $10 million a year,” he told CPAC attendees.

The Kentucky Republican closed his speech by vowing to fight the controversial decision until the courts overturn it.

“No president is more powerful than the Constitution,” he growled as applause drowned out his final statements.

McConnell was followed later in the afternoon by House Speaker John Boehner, who was similarly emphatic about fighting the president’s contentious requirement. Boehner promised the GOP will find a way to strike down Obama’s move — and they’ll do it with full transparency in the public eye.

“This is exactly how the House will deal with Obama’s recent attack on religious freedom in our country,” he said. “…We’re going to handle this openly and deliberately, so every lawmaker can have their say and the voice of the people can be heard.”

Elected officials weren’t the only ones to weigh in on the contraceptive fiasco.

During a panel discussion on “what to expect in 2012,” National Review Online editor-at-large Jonah Goldberg cautioned that conservatives should view Obama’s maneuver as not just a social issue. He deemed it a constitutional matter that dates back to the health care reform law championed by Obama in 2010.

“It’s absolutely evil to force these institutions to violate their consciences,” Goldberg said. “But this is exactly what you expect when the federal government takes over something essential to our lives like health care.”

In his acceptance speech for the National Rifle Association’s Defender of the Constitution Award, Virginia Attorney General Kenneth Cuccinelli also used the convention’s largest stage to decry Obama’s mandate.

“Assaulting our religious institutions — we know that it has to be stopped,” he said from the Marriott Ballroom. “Certainly the founders would think so.”

One of the few speakers who seemed to steer clear of the hot-button issue was Rep. Paul Ryan, R-Wis., who delivered the keynote address at Thursday night’s presidential banquet.

Instead, the House Budget Committee chairman urged Republicans to “go bold” in 2012 and not just target Obama and Democrats but also reshape the political landscape altogether.

“Look, I know that there are people in this town who are terrified at the prospect of an election with alternative visions at stake,” Ryan said, presumably referring to his drastic debt-reduction plan. “I’ll admit the easy way is always tempting. My friends, if that’s all that we stand for, then what are we doing here at CPAC?”