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"Whenever we get tired of hitting them on Romney's taxes, we'll hit them on Medicare." 

-- A Democratic strategist and former adviser to Barack Obama's 2008 presidential campaign talking to Power Play. 

Democrats are giddy over Mitt Romney's selection of Paul Ryan as his running mate. It's the pick that launched 1,000 Medicare attack ads.

Ryan, the intellectual center of gravity for fiscal conservatives in Washington, is a favorite bogeyman for the left because of his budget plan that not only caps federal spending but also transforms Medicare into a voucher program.

At 42, Ryan has already made himself into the most listened-to Republican in Congress on fiscal issues. Recall that in his early days as president, Barack Obama cited Ryan as one of the Republicans who were "serious" and who merited working with.

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    Those days are long gone, but the underlying sentiment that Ryan is a grownup in a town dominated by childish minds still remains.

    The Obama Democrats, though, have decided to cast Ryan as a hardcore ideologue. Since the Republicans took control of the House, Ryan has been cast as one of the chief villains in the Democratic melodrama in which Republicans are murderous vampires feasting on the middle class.

    Ryan doesn't shrink from the attack. His line in his announcement speech in Norfolk that "Our rights come from nature and God, not from government," was the simplest, shortest encapsulation of the conservative creed. That's not what someone who's moving to the middle would say.

    Ryan is ready to fight the ideological fight and savors nothing more than doing battle on policy points and the intellectual underpinnings of the powers of spending and taxation. He is a wonk warrior. This is helpful to Romney in keeping together a base frustrated by the candidate's perceived lack of boldness on policy. Ryan is the living embodiment of what has been branded "reform conservatism," a strain of ideological DNA on the right that is not focused on stopping the march of the left but on remaking the federal government.

    A pick who is explicitly ideological has caused anxiety among some Republicans. Not only does it open the GOP to more intense attacks on Medicare and Social Security, jeopardizing votes with seniors in graying states like Florida, Pennsylvania and Ohio, but also that Ryan doesn't add much in the way of a visceral reaction from the middle-class swing voters Romney needs so much.

    Ryan's highbrow conservatism, earnest presentation and boyish charm give him great appeal in Washington, but what about Washington County, Pa.?

    That's all true. But the selection comes at a moment when Romney is reeling a bit from many months of the most sustained, personal character assault ever launched by an incumbent president. The bile poured out on the Republican nominee since April has corroded his image. Obama is turning the Romney narrative of business turnaround artist and making him into a "vampire" who cheats the IRS and lets grandmothers die of cancer.

    However much risk comes from Ryan's policy provisions, Medicare and Social Security policy is still a debate that Romney would rather have than one about his tax returns or the Cayman Islands.

    Democrats maintain that they can do both, ripping Romney personally and then following up on policy attacks. But the truth is that if the president chooses to go for the "Mediscare" route, that will truly become a centerpiece of the campaign.

    In 2004, when John Kerry was being sliced to ribbons by an outside ad campaign accusing him of phony heroism and betrayal surrounding his Vietnam service, Kerry opted for a pleasantly bland running mate in John Edwards. The puffy pick was designed to not court controversy and make the upper-crusty Kerry more relatable to blue-collar voters.

    Romney has gone the other way and laid the bait for Obama, asking if the president would really like to have a "choice" election after all. Obama would have no doubt be better off to continue pummeling Romney's character, but he and his party may not be able to restrain their burning anger toward Ryan and his budget.

    Chris Stirewalt is digital politics editor for Fox News, and his POWER PLAY column appears Monday-Friday on FoxNews.com.