Supporters of Republican presidential candidate Rand Paul campaign for him on a busy street corner during morning rush hour on Feb. 1 in Des Moines. (Win McNamee/Getty Images)

IOWA CITY, Iowa — Ron Paul was trying to spread the gospel, and the microphone wouldn't let him. On Sunday night, more than 1,000 voters, mostly young, had crowded into the stateliest and largest room of the Memorial Union to hear Paul rally with his son, Sen. Rand Paul (R-Ky).

And then, after a standing ovation, the three-time presidential candidate sounded like an old recording of a ghost. He powered through, with only four TV cameras — two of them from C-Span — following the man who'd won 30 percent of the vote in this county four years ago. His crowd strained to hear him, until finally, someone handed him a working microphone.

"Should I start over?" Paul asked. "Okay ... remember how I used to say, 'End the Fed'?"

It was like nothing had gone wrong. "End the Fed!" yelled college students wearing Ron and Rand Paul gear. "End the Fed!" A bearded man silently raised the sign he'd made by taping together the father's 2008 logo and the senator's little icon of a flame. Steps away, the senator quietly applauded.

In the final hours before the Iowa caucuses, Rand Paul is trying to reignite the movement that his father built. In 2012, Ron Paul won 26,036 votes here, racking up his best margins in college towns such as Iowa City and Cedar Falls and Fairfield. Rand Paul always expected to build on that, but his triangulated "libertarian-ish" politics — and the rise of Sen. Bernie Sanders (I-Vt.) — saw outsider energy flow to other candidates.

For months, as analysts have speculated when he'll quit the race, Paul has insisted that he would "surprise a lot of people" by turning out "liberty" voters, including at least 10,000 college students. If turnout resembled that of 2012, that would be good for at least 8 percent of the vote, better than Paul has performed in any poll for months.

The logo of Paul's "Iowa 10,000" campaign was everywhere on Sunday -- a black-and-white photo of the senator wearing dark sunglasses. The bet is that the sort of college students who supported the elder Paul in early January caucuses, during winter breaks, would be even easier to turn out for Feb. 1 caucuses.

"I think we're going to shock people," said Austin Thorpe, 19, a student and caucus campaign for Paul in Blackhawk County. "We've been going into bars and just striking up conversations with people. We'll bring a petition for the legalization of medical cannabis, we'll start talking, and you'll find that people really respond to the message."

That was the sort of libertarian outreach that had struggled for years, despite the apparent popularity of the issues. Then came the 2008 and 2012 Paul campaigns, which found a constituency for anti-war rhetoric and the return to the gold standard. At the "Revolution Continues" rally, Ron Paul gave a 15-minute version of his classic stump speech, delivered without notes, which can sound at times like someone reading from a Bastiat text opened to a random page.

"There's a lot of illegal, unconstitutional wars going on, and too much killing, and it's coming back to haunt us," he said. "Remember what we always say: Liberty is popular!"

With the audio issues resolved, Ron Paul introduced his son as "the next president of the United States." The senator ditched his usual collection of riffs and read from a teleprompter. The text, mostly debuted in a pre-debate speech at Drake University, eschewed any talk of social issues — which had been a major part of Ron Paul's campaign — and focused on war, spying, taxes and sound money.

"Ted Cruz, Donald Trump and Marco Rubio will tell you that they want to carpet bomb the Middle East," Rand Paul said. "Cruz wants to ‘make the sand glow. Trump says we have been 'too afraid' to use our nuclear weapons. I am the only candidate who asks, will indiscriminate bombing of civilians create more new terrorists than it kills?"

The Paul "revolution" had never threatened the Republican Party's nominating process the way that Sanders had. Like Ron Paul, Sanders was becoming a pop figure among young voters in part because of his squareness and bluntness. Rand Paul, closer in age to the students, was more keen to introduce pop references. He quoted from Pink Floyd — "shine on, you crazy diamond" — and compared Donald Trump to a pathetic villain from the work of J.R.R. Tolkein.

"This race should be about which candidate will protect you from an overbearing government, not which candidate will grab the ring of power," Rand Paul said. "Electing Gollum should not be our objective."

When the speech ended, Rand Paul beckoned his audience to stand and cheer behind him as he did an interview with Fox News. Working the back of the crowd was Rep. Thomas Massie, 45, who was elected with the help of a pro-Ron Paul super PAC and who had driven 15 hours from home to stump for Rand Paul. It had been a week since the Democrats in Kentucky finally convinced Jim Gray, the mayor of Lexington, to run against Paul. In Washington, the Gray bid was seen as signal for Paul to abandon his presidential bid — not, in other words, to pursue it through every primary and caucus, building liberty-minded GOP chapters in every state, as Ron Paul had.

Massie, who was considering doing a poll of his own to prove Rand Paul's strength in Kentucky, said that the senator only had to beat expectations by a little to hush the critics.

"If he comes in fourth, this is a victory," he said.