TAMPA, Fla. — The future of what Ron Paul started rests with supporters like Ashley Ryan, who will attend Mr. Paul’s final presidential campaign rally here with decidedly mixed feelings.

Ms. Ryan, a 21-year-old college student, will take over as Maine’s national committeewoman after sitting as a Paul delegate at this week’s Republican National Convention. But in a credentials dispute, hard-bargaining party leaders left Paul forces with only half the Maine delegates they thought they had won this year — a blunt reminder of Mitt Romney’s grip on the proceedings.

“It was a huge slap in the face,” Ms. Ryan said. Though her unseated Maine colleagues can attend with guest passes furnished by the Iowa delegation, she said, “I was very disappointed.”

Yet Mr. Paul’s supporters can celebrate achievements that an earlier generation of libertarians never tasted. Despite Tropical Storm Isaac, Mr. Paul is still scheduled to stage a valedictory rally on Sunday before an estimated 10,000 supporters at the University of South Florida’s Sun Dome. Its speakers, including Ms. Ryan, were planning to send the Republican Party a message about their commitment to grow in influence as the 77-year-old Mr. Paul moves on.