Former Rep. Ron Paul, R-Texas, attacked the top-ranked Republican presidential candidates hours before Thursday's GOP debate for embodying "authoritarian" views on how to govern the nation.

In an interview on MSNBC's "Meet the Press Daily," Chuck Todd asked Paul if there were aspects to his libertarian message that Donald Trump or Ted Cruz have tried to co-op and whether it was possible that he would endorse either man.

"Impossible. I think they're authoritarians, and libertarians are not authoritarians," Paul said.

The two-time presidential candidate said the Trump and Cruz are not noninterventionists when it comes to foreign policy, which is a fundamental belief of Libertarian Party members.

Paul has been long-opposed to Trump's campaign. He told the Alan Colmes radio show last June the self-funded billionaire was "dangerous" because his message is one of, "'I know the answers and I'm going to do this and I've done this, I've done this, this and this.'"

The only candidate Paul said he would support for president is his son Rand.