WASHINGTON — Sen. Rand Paul, R-Ky., is trading insults with a longtime adviser to fellow Sen. John McCain, R-Ariz., who maintains that Paul is either a liar or in the thrall of conspiracy theories.
"I would give him the benefit of the doubt but I'm not sure which characterization — dissembler or crackpot — would be more generous," Mark Salter, McCain's former chief of staff and senior adviser for the senator's 2008 presidential campaign, wrote in a column for the website RealClearPolitics.com.
Paul's office responded to the column with a statement slamming Salter, who is close with McCain and has co-authored several books with him.
"Mark Salter advised the Republican Party down a losing electoral path that paved the way for two terms of President Obama, so people should read his angry screed in that context and disregard it," said Brian Darling, Paul's senior communications director.
Salter's column was prompted by Paul's false claim that McCain had met with representatives of the Islamic State during a visit to Syria last year.
The feud is the latest sign of tensions over national security between Paul, a likely presidential candidate with a Libertarian side, and more hawkish Republican Party voices. Paul and McCain clashed over McCain's support for funding Syrian rebels as part of the fight against the Islamic State.
Paul has also traded barbs with Texas Gov. Rick Perry, who suggested Paul was ignoring the crisis in Iraq, and New Jersey Gov. Chris Christie, who questioned Paul's opposition to the sweeping surveillance practices of the National Security Agency. Perry and Christie are also possible presidential candidates in 2016, and the debates likely will echo into the coming campaign for the Republican nomination.
Paul, who initially questioned the need for military action against the Islamic State, now supports airstrikes against the group but opposes arming Syrian rebels.
Paul made the debunked claim that McCain had met with the Islamic State, also known as ISIS or ISIL, to bolster his argument against arming the rebels.
"Here's the problem," Paul told The Daily Beast in an interview last week. McCain "did meet with ISIS, and had his picture taken, and didn't know it was happening at the time. That really shows you the quandary of determining who are the moderates and who aren't."
McCain never met with the Islamic State, despite Internet rumors to the contrary. He met and was pictured with fighters associated with the Free Syrian Army, a rebel group that opposes the Islamic State.
Salter wrote that Paul's claim shows "he is completely unsuited to his apparent ambition — election to the presidency."
"Rand Paul either still believes the falsehood, which makes him a fool, or he has decided to defame a man — who suffered greatly for his country — by accusing him of consorting with the enemy, which makes Paul despicable," Salter wrote.
Darling responded in his statement that "Americans have the greatest respect for Sen. McCain's service to his country yet McCain's former staffer used Sen. Paul's statement as a pretext for mud slinging and name calling."
Salter suggested that Paul is an immature fringe figure, an example of "conspiracy fetishists" in politics.
"All of this raises obvious questions about the sincerity of Paul's recent efforts to moderate the paranoid radicalism that so delights 9/11 deniers and Ayn Rand fanboys who are the foot soldiers of the would-be Ron and Rand Paul revolution, but will cause most voters quite sensibly to reject him," Salter wrote.
McCain's wife, Cindy, tweeted a link to Salter's column, titled "Rand Paul's Smearing of John McCain."