CHARLOTTE, N.C. — At a sunny rally here on the eve of Tuesday's Republican Senate primary, Sen. Rand Paul (R-Ky.) called Republican Senate candidate Greg Brannon a "dragon slayer" who would not be simply a "Democrat light" if elected to the Senate.

Brannon, in turn, called Paul "the next president of the United States."

The rally, attended by more than 100 in a plaza outside the NASCAR Hall of Fame, was intended to boost last-minute support for Brannon, who polls show is trailing North Carolina House Speaker Thom Tillis for the Republican nomination. Tillis was endorsed Monday by Mitt Romney.

But the campaign stop felt more like an early preview of a Paul presidential candidacy, all the more so since potential 2016 rivals for Paul have backed Brannon's opponents in the eight-candidate field.

Last week, former Florida governor Jeb Bush, who has acknowledged he's thinking about running for president, backed Tillis. Former Arkansas governor Mike Huckabee recorded a robocall for the third leading candidate, Baptist minister Mark Harris.

Paul merely smiled at Brannon's praise, but the crowd cheered appreciatively. Afterward, he told reporters it was "too complicated" to see the race as an early test of 2016 Republican constituencies. He said the divided support was merely a sign that the GOP is a "big party with many voices."

But a number of attendees in the crowd, who included a number of supporters wearing t-shirts for Ron Paul, the Kentucky senator's father, said they were gearing up already for a Paul presidential race against Republicans they view as more establishment, like Bush.

"The Bush name is toxic," said Scott Jordan, 29, a web developer from Charlotte who said he will support a Paul presidential bid. "George Bush ruined it for the family…It took some conservatives some time to see it, but he's no conservative. And his brother is no conservative either."

The winner of the primary will face vulnerable Democratic incumbent Sen. Kay Hagan in November, but the nomination battle will go to a July run-off if none of the eight Republicans gets more than 40 percent of the vote. Polls show and most strategists believe Tillis will likely take first place Tuesday and the only mystery is whether Brannon or Harris can hold him below the threshold necessary for a run-off.

Brannon told reporters he believes his campaign has pulled ahead and he could still win outright. A Paul political adviser said the polls have been fluid and the senator believes his visit could make a difference in the vote.

"Send us a champion!" Paul exhorted the crowd. "Send us an ally!"

"Some say we don't have to believe in anything—we just need to win elections," he said. ""I'm here because Greg Brannon is a believer, and we need believers."

A voice rang out from the crowd: "We want to win though!"