Just 15 months after a huge election victory, members of a fractured conservative movement gathered on Thursday to agree on one thing: If they don’t get their act together soon, the country will really be in trouble.

“Being America has changed the world and made it better,” Sen. Marco Rubio (Fla.) told the crowd on the first day of the Conservative Political Action Conference. But that basic identity will be at risk, he said, if Republicans let President Obama win reelection. “We must decide if we are prepared to continue that, or to recede and become just like everybody else.”

CPAC — a rollicking combination of trade show, political rally, and support group for College Republicans — opened with the usual happy tossing of red meat. One congressman used his time to decry mandates for low-flow toilets: “We are a nation of double-flushers!”

But even in the convention’s early hours, there were signs of the tension that threatens to pull apart the movement. And each of the four Republican presidential campaigns is trying to grab the biggest piece.

“Our goal is to be the counter-Mitt,” said Aaron Harvey, 37, a volunteer for former House speaker Newt Gingrich (Ga.). He was standing at the bottom of an escalator at the conference, trying to hit up supporters of former Massachusetts governor Mitt Romney and former senator Rick Santorum (Pa.) in the two seconds as they passed.

“I like Rick. He’s a good guy,” Harvey was telling one Santorum supporter. But Gingrich has better ideas, Harvey said. And he’s ready to lead. “Rick’s a young guy. He’s got time.”

The conference, in its 39th year, provides a sampling of American conservatism. The attendees included businessmen in the Platinum and Diamond sections, and young activists in a “Conservative Dating” class (“What’s your definition of attractive?” the leader asked a young man in the front row. Healthy-looking hair, he answered.).

The CPAC exhibitors ranged from the mainstream, such as the Republican National Committee, the National Rifle Association and the Heritage Foundation, to groups deep into the party’s niche issues. One T-shirt for sale showed a handgun and the slogan “I Don’t Dial 911.” Another group, which says its members are lay Catholics who defend Christian morals, displayed the slogan “Neither Apostasy nor Dhimmitude.” (“Dhimmitude” is a term some activists use to mean submission of non-Muslims to Islamic law).

On Thursday, a series of activist leaders and Republican officials took the main stage to repeat one another’s argument: The country is facing an existential crisis.

“We are on the precipice of an abyss,” said Colin Hanna, president of the group Let Freedom Ring USA, arguing that Obama, if reelected, would let the federal debt grow to more dangerous levels.

For Rep. Tom Graves (Ga.), the key metaphor wasn’t a cliff. It was a book. Obama, he said, would alter U.S. culture so much as to end the American narrative that began with the Founding Fathers. “The decision to end this great story we call America,” he said. “Close the book, or turn the page. The choice is ours.”

For Rep. Steve King (Iowa), the right metaphor for the country’s troubles wasn’t a cliff or a book. It was a low-flow toilet.

King, a tea party favorite, described his efforts to avoid government mandates designed to save energy or water. He bought old-style light bulbs to replace curly compact flourescents that made his office too dim. He tore out a water-saving showerhead, which had extended his showers from three to 12 minutes with its low flow. And he raged at his toilet, outfitted to save water with smaller flushes.

King compared the regulators who imposed these orders to the East German secret police, the Stasi. “I want my liberty back,” he said.

These messages were all a kind of warning that conservatives must unite, or watch Obama win and make things worse. “Now, the trick is to stick together,” said Senate Minority Leader Mitch McConnell (Ky.).

For some in the crowd, unity mattered more than any particular candidate. When asked whom he is supporting, Guy Siebold of Fairfax County said “ABO”: Anybody but Obama.

“Think of a thermometer outside — 92 degrees, 94 degrees, 97 degrees, 86 degrees — those are your Republican candidates,” he said. “Minus-12 — that’s Obama. . . . The flaws of the individual [GOP] candidates are insignificant in comparison.”

But the divisions between the candidates still bubbled up. Onstage, Texas Gov. Rick Perry, a Gingrich supporter, seemed to attack Romney without naming him.

“We need to stop pretending that the main goal of Republican governance is to do the same thing as Democrats, but just don’t spend as much money,” Perry said. “We can’t tinker our way to victory.”

At least one attendee, Jen Dicus, 21, of Medford, Ore., said she thought the flaw that Perry was harping on — Romney’s past moderate views — might be an asset.

“I think that with the political climate, with Democrats [controlling] the Senate . . . I think it might be helpful to have someone that is a little bit more appealing to both sides,” Dicus said. “I think that might kind of promote more peace between the two parties.”

Thursday was the day for presidential also-rans: Perry and Rep. Michele Bachmann (Minn.) spoke, along with former pizza executive Herman Cain, who told the crowd he learned that “we outnumber the stupid people. Trust me.”

On Friday, three remaining contenders will have their chance: Romney, Gingrich and Santorum will speak.

With the party’s message split between those three — and Rep. Ron Paul (Tex.) — the conservative movement did not seem to be heeding the main rule preached by professional dating coach Wayne Elise.

Be specific about what you want, he said during the Conservative Dating session.

“When you’re very specific and you tell people what you want, it’ll be very memorable,” Elise said.

Romantically speaking, he said, that might mean specifying what kind of person you’re attracted to. Or, when you’re on a date, saying, “I’m going to bring some Chapstick — in case there’s some making out.”

He added: “When people know what you want, they’re more likely to help you reach it.”