NATIONAL HARBOR, Md. — Sens. Rand Paul and Marco Rubio on Thursday offered the Republican Party a glimpse of alternate futures in dueling speeches that revved up two distinct groups of conservative activists.

Speaking back to back to political activists attending the 40th annual Conservative Political Action Conference, Florida’s Rubio offered a broad vision more grounded in the three-legged coalition of social, national security and fiscal conservatives that has defined GOP governing since Ronald Reagan won the presidency in 1980.

Kentucky’s Paul focused his remarks on constitutional liberty and social libertarianism, specifically calling on the Republican Party to change and evolve from the “stale, moss-covered” party he said it has become into a movement that appeals to the younger “Facebook generation” of voters that he claims questions the viability of Social Security and wants the government to leave them alone.

“I think they were both good speeches,” said Wayne Morgan, a Washington, D.C., activist and consultant sporting a Ken Cuccinelli for Virginia governor sticker. “Rubio’s speech seemed to resound, I would say, with the whole crowd. Paul’s message of freedom, rights, small-government definitely hits most of this crowd.”

Paul and Rubio each rose to prominence in 2010 on the strength of their elections to Congress as tea party stalwarts. Their profiles were similarly elevated again recently — Rubio through his selection as the Republican designated to respond to President Barack Obama’s State of the Union address; Paul via last week’s 13-hour filibuster in protest of the administration’s drone-targeting policies. Both senators are considered potential 2016 presidential candidates

Rubio was well-received by the ballroom crowd at the Gaylord National Resort and Convention Center. The Floridian quickly excited the crowd by joking about having plenty of water to drink — a reference to his rebuttal to the State of the Union, when he interrupted that speech midway through to gulp down a bottle of water.

He then offered a broad defense of conservative values and the United States as a force for good in the world. Rubio made a subtle plea for conservatives to understand those voters who look to government for help, saying the GOP should not ignore or ridicule them, but woo them, as they only want a better life for their families. But he pointedly suggested that the GOP in fact does not require a major course correction to achieve future success.

“We don’t need a new idea. The idea’s called America, and it still works,” Rubio said, to perhaps the largest applause he received during the afternoon speech.

Paul, whose last name is golden among a segment of the CPAC constituency thanks to the popularity of his father, former Texas Rep. Ron Paul, was further buoyed by enthusiasm he created in the broader conservative movement by his March 6 filibuster. At least half of the ballroom crowd appeared to stand throughout the duration of Paul’s remarks, and the vigorous applause at times appeared heavier than what Rubio received.

But what was most poignant about Paul’s speech was that it comes at a time when the Republican Party continues to plot a path forward in the wake of a disappointing 2012 Election Day. And, Paul, who addressed the crowd wearing faded jeans and a suit jacket, in no uncertain terms challenged the GOP to chart a different course or fade into irrelevancy at the national level.

“Liberty must be the backbone of the GOP,” Paul said, both in the economic and personal sphere, adding that Republicans must “show up” on the south side of Chicago and proclaim the GOP to be the party of opportunity for all Americans.