We have learned, in the three short days since Paul Ryan was catapulted into the national spotlight, that he skins and butchers animals to make his own Polish sausage (courtesy of The New York Times). That he is “pretty low-maintenance” (as his wife, Janna, tells People). That he is “kind of hot” (thank you, Politico), and that the second–most popular search term for Ryan is “shirtless” (fun fact from The Washington Post). Not to mention he’s a former altar boy and a fitness buff.

In short, a rather wonkish congressman known primarily for his budget-slashing prowess is in the full flower of a media honeymoon. At the moment, he looks like a stellar pick who has accomplished the daunting task of loosening up Mitt Romney.

But watch out: Romney’s choice may look very different in the coming weeks.

It’s not that the mainstream media have ignored Ryan’s long record of wanting to drastically shrink and revamp government programs, especially Medicare and Medicaid, while pushing tax breaks that disproportionately favor the wealthy. But this somewhat radical agenda is wrapped in the gauzy overlay of an earnest young man who genuinely wants to keep the country from marching off a fiscal cliff.

Even the liberal Slate editor Jacob Weisberg says Ryan is not a “heartless ideologue,” but “a conviction politician who has changed his party far more than it has changed him.” Weisberg had questioned Ryan at a press breakfast, underscoring the House Budget Committee chairman’s hidden asset: a cordial relationship with reporters and pundits in Washington and New York.

But the press won’t long be satisfied recounting his roots in Janesville, Wis., and how he went to work at McDonald’s at 16 after his father died. For all the hopeful chatter that Ryan’s selection could produce a serious and substantive election debate, the hyperspeed news cycle and relentless distortions of modern political campaigning will probably render that a fantasy.

Ryan may have energized the right—Rush Limbaugh and Rupert Murdoch appear ecstatic about his elevation—but the congressman has a long paper trail that could alienate moderate swing voters. If Newt Gingrich could assail Ryan’s Medicare plan as “right-wing social engineering,” little wonder that the Obama team is salivating over the prospect of hanging the Ryan record around Romney’s neck.

Ryan’s plan to turn Medicare into a voucher program, adopted by the House, could wind up costing future retirees $6,000 a year as medical costs outpace the fixed benefits, according to independent studies. Conservatives are pushing back against this assessment, with National Review publishing several pieces Monday on the Democrats’ “Mediscare” tactics.

But the details—that Ryan has changed his original plan, that seniors would have a choice of plans and some would be subsidized by the government—are complicated. Kind of like the way that Obamacare is difficult to explain. And if the voucher plan didn’t cost elderly recipients a dime, how much money would it save?

Ryan’s response is that his plan is preferable to the Democratic approach of doing nothing (though how does that square with the charge he and Romney make that the president wants to cut $700 billion from Medicare?).

Romney insists the duo is running on his proposals, not his VP nominee’s. On Monday, he declined to discuss the differences between his Medicare plan and Ryan’s, saying, “We haven’t gone through piece by piece.” But that won’t wash. Even Fred Barnes, while praising the choice in The Weekly Standard, says: “Now Romney must actively promote and defend the Ryan plan. As of today, it’s the Romney plan.”

Then there is Ryan’s support for a “personhood” bill that would declare life begins at conception. Not a great help to a presidential candidate who wants to get rid of Planned Parenthood.

Ryan also has pushed to privatize Social Security, which George W. Bush, despite the congressman’s help, couldn’t even get to a vote. Think that will play well in Florida?

And as the Times noted, Ryan has voted against requiring more stringent background checks for buyers at gun shows, and against federal funding for NPR.

Perhaps most difficult for Ryan to explain is why a self-professed fiscal hawk voted for the TARP bailout and Bush’s Medicare prescription drug program, and why he insists on zeroing out capital gains taxes and protecting the Pentagon from even modest cutbacks.

Most voters won’t delve into all these details, of course. But Democratic attacks will paint Ryan as a man who would squeeze the middle class and the elderly while fiercely protecting the hedge-fund crowd. Keep in mind that half the country has never heard of Paul Ryan, so his political persona has yet to be defined.

That’s why any celebration of Romney’s pick may prove to be premature. Ryan, who has never run for anything outside his Wisconsin district, may appear a very different political figure by September. At the very least, he shifts the campaign focus from Obama’s economic record to what the Romney-Ryan team would do to entrenched social programs.

The Romney team knows all this. BuzzFeed reports that all the top advisers opposed Ryan, except for the man at the top of the ticket. It was a far riskier choice than some of the more glowing profiles would suggest.

So Ryan should go ahead and enjoy such features as The Washington Post’s “Everyman With Extraordinary Charm.” This phase won’t last long. The press is a fickle beast, and it has only just begun to sniff around Paul Ryan.