The chairman of the Republican National Committee, Mike Duncan, had a private meeting with Paul in April to discuss the future of the party but no decision has been made yet on speaking roles at the convention, according to an RNC official.
Virginia conservative Farris says the lack of enthusiasm among some social conservative leaders should worry McCain.
"He's not gone out of his way to win over people concerned about his record," he said. "If he doesn't, he's asking for more dissension. He needs to solidify that base. If he dampens the enthusiasm of even a small percentage, in a close election that could be crucial."
Farris notes that Republican voters need positive reasons to vote for their candidate. "Unfortunately, it's coming down to whether you like [Democratic Sen. Barack] Obama or not. We can't win if it's just based on negative reasons not to vote for the opposing candidate."
Farris also denied a story by syndicated columnist Robert Novak reporting that he promoted an Obama candidacy as a biblical justification.
"I've never said or heard such a thing," he said, noting that he probably will vote for McCain. "I don't talk in terms of Old Testament plagues. One thing we learn is that they're undesirable so the fact that I would desire something like that doesn't make sense."
Huckabee posted a denial on his political action committee's Web site, reiterating his support for McCain and stating, "The nonsense that I want Obama to win this year so I can run in 2012 is absurd. I love my country more than my own ambition."
As for Paul, although he only has collected 19 delegates so far compared to McCain's 1,413, he plans on bringing them to the convention and stressing his limited government agenda, which includes abolishing the Federal Reserve and the Internal Revenue Service.
Paul is also insisting on a speaking opportunity at the convention, which the GOP has yet to offer.
As for Barr, his spokesman says that the Libertarian Party typically attracts more voters from the Republican side.
"Any third party can be a potential spoiler," Barr spokesman Andrew Davis says. "Ross Perot did it in 1992. Our party competes just like any other party does."