Republicans were a bit giddy yesterday over the selection of Rep. Paul Ryan (R-Wis.) as Mitt Romney’s running mate. Fay, a retiree, attending Romney’s rally in Manassas, Va., told me that she was delighted: “My three children voted for Obama last time. They’re not voting for him again.” She likes Romney and Ryan because they “believe in America.” A couple in their mid-40s said that their 13-year-old son dragged them to the rally. The mother said that Obama turned out to be “not as great as we thought he’d be.”

Among Republican policy mavens and officials it was hard to find someone who wasn’t delighted.

Late yesterday I spoke briefly with Virginia Gov. Bob McDonnell (R), widely thought to be on Romney’s short list of candidates. Was he disappointed? “Heck no! He made a great choice,” he said of Ryan. He told me, “I saw him this morning. We shared a good handshake and a hug. I told him, ‘It’s a good thing I arranged to get the [USS] Wisconsin here [to Norfolk].” McDonnell saw a “great chemistry” build through the day. He has observed firsthand the heightened excitement about the chance to vote out Obama. “I’m seeing it in a couple of ways. There are the number of calls and volunteers compared to 2008.” He also has seen a stream of GOP officials “willing to go out and be surrogates,” as well as an uptick in fundraising “even in the blue parts of the states.” That, he expects, will only increase with Ryan on the ticket.

Over at the American Enterprise Institute, where Ryan has been a frequent speaker and a favorite of conservative wonks, AEI President Arthur Brooks said succinctly, “Aspiration has won the day over caution. It is an inspired choice.”

In foreign policy circles, where the issue of Robert Zoellick’s appointment to head the transition team on national security riled hawks, there was an outpouring of enthusiasm.

Liz Cheney e-mailed me, “Ryan is a fantastic pick — a man of substance, character and courage. The American people will now get to know, in this GOP ticket, two true leaders who won’t shrink from tough decisions and who know what it will take to get America growing again. Plus — Obama and Biden are now clearly the failed old guard. Romney and Ryan are the future.”

Danielle Pletka, AEI’s vice president for foreign and defense policy, e-mailed from Spain, “ Ryan is awesome pick. I’m not a pollster, but I am a voter, and Paul is smart and principled. No president or vice president will ever know everything about everything, which is why they need signposts to guide them.” She continued, “Paul’s signposts are a strong America, a responsible government and a nation that puts enterprise and freedom over handouts and servitude. Those signposts apply to Americans and to pretty much everyone else; believe in the right thing, and you’ll support a foreign policy that values freedom. The rest is window dressing.” John Bolton, her colleague, a former U.S. ambassador to the United Nations and a key foreign policy adviser very likely to sang a top spot in a Romney-Ryan administration, released a statement: “Every American and every American ally abroad should be heartened by Mitt Romney’s selection of Paul Ryan as his running mate. Congressman Ryan deeply understands that American leadership in foreign policy makes for a more peaceful world and a safer, more prosperous America. And he and Governor Romney will restore our economic strength at home that is the basis of our influence abroad. For nearly four years, we have seen the dangerous conditions that are created when a president refuses to lead. Mitt Romney and Paul Ryan will restore American leadership.”

In short, the base is delighted and the roll-out went as well if not better than the Romney team expected. (At the Manassas rally senior campaign advisor Stu Stevens was beaming.) But the hard part is just beginning. Ryan will come under tremendous scrutiny and will try to expand Romney’s appeal in middle-class suburbs. If he does what his admirers think he is capable of, he’ll be a rare commodity n D.C.: a widely respected vice president who is the butt of no jokes. That would certainly be a change.