Senator John McCain is sailing toward his coronation as the Republican presidential nominee while the Democratic candidates battle fiercely. But Republicans also are engaged in some tough infighting that could disrupt the national convention and make it more difficult for him to unite the party in the fall.

Across the country, at state and county GOP conventions, diehard supporters of maverick Ron Paul are staging uprisings in an effort to secure a role for Paul at the national convention in Minneapolis-St. Paul.

And in the four primaries since clinching the nomination in early March, McCain has yet to reach 80 percent of the vote, as Paul and former Arkansas Governor Mike Huckabee continue to siphon away votes, even though Huckabee has withdrawn from the race.

The lingering anti-McCain sentiment among some voters and the continuing Paul insurgency suggest that McCain has not fully quelled hostility from some elements in his party.

Paul remains the lone holdout who is still actively campaigning. He has indicated he is unlikely to endorse McCain, and his zealous supporters have turned out in large numbers to battle for delegates at recent GOP gatherings in Maine, Minnesota, Missouri, Nevada, and Oklahoma.

The Paul supporters do not see themselves as fighting for a hopeless cause, but as members of a new movement founded on libertarian principles. Paul's newest book, "The Revolution: A Manifesto," has soared quickly to number one on the New York Times bestseller list.

"This is about continuing the message and having a voice of freedom, constitutionalism, and peace inside the Republican Party," said Paul's Maine coordinator, Ken Lindell, a former state representative. "The goal at the national convention is to get a speaking slot for Dr. Paul to deliver that message."

Other Paul loyalists say they may try to open debate on the party platform at the convention in early September. Paul, a congressman from Texas, opposes the war in Iraq and what he describes as an interventionist US foreign policy.

He also advocates minimal government, abolishing the Internal Revenue Service, and a return to a monetary policy based on the gold standard.

Paul has 19 delegates to McCain's 1,413, the latter being well more than the 1,191 needed for the nomination, according to the latest Associated Press unofficial tally. Paul's campaign, which shattered online fund-raising records early in the campaign, had $5.1 million in cash at the end of March.

In Minnesota, Paul loyalists captured seven delegate slots at congressional district meetings, and in Nevada, the convention abruptly recessed on April 26 after balloting showed Paul supporters winning at least half of the initial contests for delegate slots to the national convention.

"We want them to know we're not going to roll over any more, and as long as [Paul] is running, we'll stand by him," said Arden Osborne, a Paul supporter and chairman of the Nevada Liberty Alliance. Osborne believes he won one of the slots to the national convention during the state convention in Reno.