AUSTIN, Texas — Republican Ron Paul ended his rebel campaign Thursday night and announced a new effort to help elect libertarian-leaning Republicans to public office around the country.

"With the primary season now over, the presidential campaign is at an end. But the larger campaign for freedom is just getting started," Paul told supporters in a letter posted on the website of the new group, Campaign for Liberty.

"We will be a permanent presence on the American political landscape," added Paul, who announced his move during a rally coinciding with the Texas GOP State Convention in Houston. "That I promise you. We're not about to let all this good work die. To the contrary, with your help we're going to make it grow - by leaps and bounds."

The 72-year-old Texas congressman won 24 delegates during the Republican primaries, but was the last remaining challenger to John McCain, the party's presumptive nominee.

Paul has said he won't endorse McCain, but in an interview with CNN earlier Thursday, Paul had nice things to say about Bob Barr, a former Republican congressman from Georgia who is the Libertarian Party's nominee. Barr "talks our language, so I do really believe that he can have a very positive effect in this campaign and let the people know that limited government is a very, very important message," Paul said.

Paul raised more than $34 million, much of it online, and had more than $4.7 million in hand at the end of April that he could use to fund Campaign for Liberty.

He also developed a large grass-roots following among those who backed his call for ending the war in Iraq and smaller government at home. He easily passed the 1 million-vote mark during the primaries, and in the final three contests on June 3 he finished second to McCain, with 22 percent of the vote in Montana, 17 percent in South Dakota, and 14 percent in New Mexico. His new book, "The Revolution: A Manifesto," zoomed to the top of bestseller lists.

Supporters, staging uprisings at state and county GOP conventions across the country, have pushed for a speaking role for Paul at the Republican National Convention in September in St. Paul.

Because that does not appear likely, Paul confirmed plans Thursday to hold a counter-rally at an arena in neighboring Minneapolis on Sept. 2, the second day of the GOP convention.