Rock music pounded out of the speakers and the waiting crowd was at one point treated to back-to-back songs by Kiss, first “Detroit Rock City” and then “Shout It Out Loud.” However, the crowd gathered on a hot Saturday afternoon inside the Harris Pavilion in Manassas, Virginia, wasn’t there for a concert. They were awaiting the arrival of the new-minted Republican presidential ticket, and the excitement generated by Mitt Romney’s selection of Paul Ryan as his running mate was hard to miss as thousands crowded into downtown Manassas for the event.

How big was the crowd? Huge. Enormous. Gigantic. It was difficult to get an estimate because the audience attending the rally overflowed the pavilion (which has an official capacity of 1,000) and filled the surrounding plaza. Lines to get into the venue circled around several blocks and, when Romney and Ryan arrived, there were still hundreds waiting to get through the metal detectors. Susan Ferrechio of the Washington Examiner, who rode into town on the press bus, shot a photo of the crowd lining the streets of Manassas that prompted the paper’s editorial page editor Mark Tapscott to muse that the polls must be wrong: “How to explain such crowds if Obama is leading in Virginia, one of the key swing states?”

Indeed, it is hard to reconcile Saturday’s enthusiastic Republican turnout for the Romney-Ryan tour of Virginia with polls showing President Obama ahead in the Old Dominion by 3.2 points in the Real Clear Politics average. The prosperous Northern Virginia suburbs of D.C. are the crucial “swing” section of the Commonwealth, and a strong GOP wave in the 2009-2010 elections — electing Bob McDonnell governor and defeating three incumbent congressional Democrats — would seem to indicate Virginia has returned to the Republican column. (See my July 16 report, “Battleground Virginia.”) Yet the Romney campaign can’t afford to take the state for granted, which probably explains why Romney announced his running mate pick in Norfolk at the beginning of a daylong bus trip across Virginia. When Romney and Ryan took the stage in Manassas for the last stop of the trip, CNN reporter Jim Acosta found himself shouting to be heard above the cheering thousands: “This is as loud as I have heard a Romney campaign rally,” Acosta told CNN anchor Deborah Feyerich. “This crowd is fired up.”

Clearly the crowd was excited by the choice of Ryan, the Wisconsin Republican who chairs the House Budget Committee, whose detailed plan to balance the federal budget has made him something of a GOP rock star. Ryan is remarkably young. Now 42, Ryan was only a first- grader in 1976 when Kiss released the heavy-metal anthems played as warm-up music at the Manassas rally. His youth is viewed as a point in his favor by conservatives with bad memories of the 2008 mismatch between the vigorous young Obama and geriatric John McCain, who lost the under-30 vote by a 2-to-1 margin. “Paul Ryan is fresh, young, energetic, smart, courageous, and ready for prime time,” syndicated columnist Michelle Malkin exclaimed in endorsing Romney’s choice. Yet as Romney made sure to remind the Republican crowd in Manassas, Ryan’s youth doesn’t mean he’s inexperienced. “This is a man who learned leadership young because leadership is a function of character and courage,” Romney said of Ryan, a seven-term congressman. “As a young man, a high schooler, his dad died and he was forced to grow up quickly.”

Ryan came to Washington fresh out of college in 1992 and worked as a GOP congressional aide before returning to his native Wisconsin to win his own House seat in 1998. His acknowledged mastery of fiscal and economic policy earned him praise from the Weekly Standard as “the Republican Party’s intellectual leader.” That article by Bill Kristol and Stephen Hayes, urging Romney to make a “bold” choice in his VP pick, was part of a 10-day flurry of last-minute speculation that was ultimately revealed as unnecessary. Conservatives feared that Romney would go with a “safe” choice like Ohio Sen. Rob Portman or former Minnesota Gov. Tim Pawlenty although, according to campaign staffers, Romney actually decided Aug. 1 that Ryan would be his running mate.

The boldness of Romney’s choice surprised some, including the mysterious blogger Allahpundit at the popular conservative Hot Air site, who invoked a science fiction analogy: “It’s like watching C-3PO lead the raid on the Death Star.” (This comparison of Romney to C-3PO, the comically effete robot of the Star Wars film series, might dismay Democrats who have spent the past several weeks trying to convince voters that Romney is actually Darth Vader.) In choosing Ryan, Romney was seen as making a bid for Tea Party support while also signaling his intent to focus the fall campaign on the economic and fiscal issues that are Ryan’s speciality. Democrats and liberal pundits immediately began chattering about what a disastrous choice Romney had made. Obama adviser David Axelrod called Ryan’s views “extreme” and MSNBC’s Andrea Mitchell declared that Ryan is “not a pick for suburban moms, not a pick for women.” Mitchell’s opinion was certainly not shared by the many suburban moms who turned out Saturday for the Romney-Ryan rally in Manassas. Female enthusiasm for the tall, dark, blue-eyed Irishman caused me to remark that Ryan’s Secret Service code name should be “Dreamy.”

Whether their enthusiasm was inspired by Ryan’s bold policies or his blue eyes, conservatives were encouraged by Romney’s choice. Ryan immediately showed himself willing to take the fight to Obama, telling the Manassas crowd that the president aspires to “a government-centered society with a government-run economy.” Obama’s policies are “not working,” Ryan said, and the president “is not going to be able to run for re-election on his record because it’s a terrible record.… He’s going to divide the country, to distract the country, to try and win this election by default.”

Ryan’s confrontational rhetoric reassured conservatives who have complained bitterly about what they see as John McCain’s failure to “get tough” with Obama during the 2008 campaign. Conservatives circulated online videos of Ryan’s previous confrontations with Obama, including one in which the Republican congressman denounced the president’s health-care plan as “full of gimmicks and smoke and mirrors.” Hillsdale College history Professor Paul Rahe hailed Romney’s choice of Ryan as a “declaration of war” on Obama. “There will be no evasion, no triangulation, no attempt to mask what is at stake in this election,” Rahe wrote. “Instead, Romney and Ryan will directly confront Barack Obama and call him to account for putting us on a ruinous course.”

Paul Ryan is clearly the kind of Republican who, as Ronald Reagan said, prefers bold colors to pale pastels. Ryan will not whisper the conservative message — he’ll shout it out loud. And judging from the reaction he’s gotten so far, Republicans are ready to rock.