In the dark days of the Civil War, Abraham Lincoln had to continually change generals as the Union Army reeled from one loss after another. The names have become a historic blur, except for the two that bookended the war: General George McClellan and General Ulysses S. Grant.  McClellan served twice as the top-ranking Union general, but Lincoln had to cashier him both times for lack of aggressiveness and unwillingness to use superior forces to wear down his opponent. After a series of other appointments, Lincoln finally chose Grant to lead the Union army, despite a mixed record and reputation. When pressed to find a more suitable commander by some in Washington, Lincoln declared: "I can't spare this man. He fights."

In a sense, that explains why Mitt Romney chose Paul Ryan as his running mate. Barack Obama set the tone for a big fight on anything but the current economic conditions, and the media has so far gone along with the distraction-a-week sound bite war. Romney needed to make the election substantive, and in order to do that, he needed to escalate the seriousness of the debate.

In 2010, Ryan picked apart the fiscal arguments Obama made to justify the Affordable Care Act as deficit-neutral — in just six minutes.

It's not as though Romney lacked good options for a running mate. Tim Pawlenty had run against Romney early in 2011, but dropped out after a bad bet on the Ames, Iowa straw poll almost exactly a year ago. The two-term former governor of Minnesota immediately became a Romney surrogate and has been on the road since, attacking Obama on his economic and fiscal record. Louisiana Governor Bobby Jindal abandoned his earlier endorsement of Rick Perry to start campaigning for Romney in May. Senator Rob Portman of Ohio, who served as George W. Bush's budget director, likewise had been considered in the top tier in part for his vigorous campaigning for Romney.

The direction of the campaign thus far showed the need for more policy heft on the ticket. The Obama team has spent $120 million and three months to paint Romney as an out-of-touch One Percenter. Those actions didn't move the polls, but they did set Team Obama up to demonize and delegitimize Romney's budgetary and economic policy during the general election season. While Romney had never explicitly embraced Ryan's budgetary reforms, Romney's plans had more similarities with Ryan's reforms than differences. Democrats had worked to tie the Ryan reforms to Romney as far back as the Republican primaries. As far back as March 23, DNC chair Debbie Wasserman Schultz called Ryan's budget the "Romney-Ryan plan" while criticizing it as a tornado through America's nursing homes." 

When Romney announced Ryan as his running mate, Democrats responded with glee, champing at the bit to attack Ryan and Romney. The Obama campaign welcomed Ryan to the race on its Tumblr site by calling him "the worst."  Obama campaign adviser Robert Gibbs told Chuck Todd that Ryan's reform would force his 83-year-old father to find health insurance, which prompted Todd to correct Gibbs, since Ryan's plan would leave current Medicare recipients on the current plan.

Democrats shouldn't get too excited about Ryan's candidacy, though, because Romney's choice shows that he's looking to have this fight.  Romney picked Ryan because he believes that this is a fight Republicans can win, and because this is a fight Ryan has already won in high-profile encounters.

In early 2010, Obama moderated a lengthy debate between Republicans and Democrats in Congress on ObamaCare. Obama wanted to show that his plan could withstand scrutiny. Instead, Ryan methodically picked apart the fiscal arguments Obama and Democrats made to justify the Affordable Care Act as deficit-neutral — and he did so in just six minutes. Ryan finished by asking, "Are we bending the cost curve down or are we bending the cost curve up? Well," Ryan continued, "if you look at your own chief actuary at Medicare, we're bending it up. He's claiming that we're going up $222 billion, adding more to the unsustainable fiscal situation we have." Obama's response? He changed the subject to Medicare Advantage.

The next year, Obama invited Ryan to a speech on budget reform, which normally would signal some sort of olive branch, or at least outreach to the opposite party to find a solution in a complicated and thorny policy area. Ryan attended, sitting in the front seat — and Obama directly criticized Ryan by name, calling his budget un-American. The Wall Street Journal blasted Obama's attack, noting that "Mr. Obama did not deign to propose an alternative to rival Mr. Ryan's plan, even as he categorically rejected all its reform ideas, repeatedly vilifying them as essentially un-American." Ryan responded by calling Obama the "Campaigner in Chief," who was less interested in "building bridges [than] poisoning wells," pointing out that the president's proposals didn't put a dent in deficits, let alone debt.  

The next month, both plans came to a vote in the Senate. Ryan's budget lost on a party-line vote; Obama's lost 0-97. Erskine Bowles, a former chief of staff to Bill Clinton, and Obama's own appointee to the deficit-control panel whose recommendations Obama completely ignored in that budget proposal, told a University of North Carolina audience in September 2011 that Ryan had proposed "a sensible, straightforward, serious budget and it cut the budget deficit by $4 trillion."  In contrast, Bowles told the audience,  "I don't think anyone took [Obama's] budget very seriously."

In February 2012, Obama proposed yet another unserious budget that ignored all of the realities of our short- and long-term fiscal shortfalls, with yet another trillion-dollar deficit. Treasury Secretary Tim Geithner tried to tell Ryan and the House Budget Committee that Obama's budget proposal would "stabilize" the deficits. This time, Ryan only needed four minutes to dismantle that argument, showing that Obama's long-term budget only "stabilized" deficits for a decade, after which they escalated out of control — unlike Ryan's long-term budget reforms, which solved the problem of escalating costs. "We're not coming before you to say we have a definitive solution to our long-term problem," Geithner finally exclaimed. "What we do know is we don't like yours."

That budget was defeated in both the House and the Senate, and failed to get a single vote in either chamber from Democrats or Republicans.

Ryan has spent the last few years fighting the Obama administration, and he knows how to do it and win. He breaks through all of the class-warfare distractions and connects well when people pay enough attention to policy debates. Romney just promoted him to the highest possible level of media attention as his general on fiscal and entitlement reform. Having twice humbled Obama in very high-profile encounters, Ryan will likely make Democrats fret about facing him every day for the rest of this campaign.