Kentucky Sen. Rand Paul broke ranks with his father's political army this week and endorsed Mitt Romney as the Republican Party presidential nominee, setting off a firestorm of outrage in the Ron Paul Universe.

Here's a sampling of the reactions from around the Internet:

As the comments suggest, Sen. Paul's endorsement appears to have seriously damaged his credibility within the Movement — at least among its most hardcore activists. The virulent backlash indicates that the endorsement could have harmful political ramifications for the Kentucky Senator, raising doubts about his ability to unite his father's grassroots army with more mainstream elements of the Republican Party base.

"I think Rand Paul believed he could build from his father's base," said Brian Doherty, a journalist who has been covering the Ron Paul Revolution since the late 1990s. "But I think he has probably found in the last 24 hours that this might prove more difficult than he expected."

WATCH: Brian Doherty Explains

The Fanatics Who Are "Ron Paul's Revolution"

But Doherty told Business Insider that he was not completely surprised that Sen. Paul opted to endorse Romney. Unlike his father, Paul has frequently shown a willingness to work with the GOP Establishment, and has previously indicated that he planned on getting behind whoever his party picked as the nominee.

"There are a lot of Ron Paul people who like to think of themselves as a ragtag rebel army," Doherty said. "But Rand Paul is clearly positioning himself to play the part of the loyal opposition in the Republican Party. Emphasis on loyal."

What was surprising about the endorsement, Doherty said, was its timing.

Although Ron Paul has admitted he is no chance of winning the GOP nomination, he is still technically running for president and announced earlier this week that he expects to have 200 bound delegates at the Republican National Convention this summer. Moreover, his campaign is still encouraging supporters to try to get elected as national delegates at state and local party conventions.

"It seems like a gratuitous kick in the face to his father's most ardent supporters," Doherty said, adding that the endorsement seems to indicate that "Rand Paul might have less respect for the grassroots movement than he ought to."

It's possible, however, that Rand Paul knew he was going to piss off his father's die-hard fans — he just didn't care.

"There's a lot more to the movement than the hard-core fanatics," Doherty said. "There are a lot of people who voted for Ron Paul [in the primaries] who are not writing angry things about Rand Paul on the Internet today."

And Rand Paul's comments during his endorsement Thursday suggest that he was at least aware of the people he was betraying:

"My dad has a legion of young followers who are on the Internet, and they think they rule the Internet," Paul told Fox News host Sean Hannity. "Maybe they do and maybe they don't."

Hindsight may show that these remarks underscored some serious political hubris. Rand Paul's political clout depends, in part, on his ability to rally these grassroots Internet activists, and get them to make noise and moneybombs.

Even if he has decided that he can give up on the most hard-core fanatics, his support for Romney threatens to hurt his credibility within the broader Liberty Movement, particularly among those who see Romney's hawkish foreign policy positions — and Bush-era national security advisors — as anathema to the movement's principles.

Still, Rand Paul's endorsement does have some obvious political benefits, at least in the short-term. Already, the endorsement has raised the Kentucky Senator's national media profile, and sparked speculation about a possible VP nod. At Friday's Conservative Political Action Conference in Chicago, Sen. Paul came in fourth place in the vice presidential straw poll with 8% of the vote, coming in one point behind House Budget Chair Paul Ryan.

When asked about a possible V.P. run yesterday, Sen. Paul told CNN "it would be a great honor to be considered."