Mitt Romney averted disaster yesterday by scratching out a win in Michigan. This allowed him to reestablish himself as the favorite for the nomination. But the other big takeaway is that Romney’s vulnerabilities are more exposed than ever and he’s now face-to-face with another contest that arguably has higher long-term stakes: Ohio.

As Amy Gardner reports in a useful overview of the looming contest, Ohio will be another stage upon which Romney’s flaws will come under the glare of a harsh spotlight. Romney’s string of silver-foot-in-mouth gaffes sets this contest up as another test of his struggles with the blue collar whites that will help decide this fall’s election — this time in a must-win general election state for the GOP.

And then there’s that auto-bailout. The perceived ideological imperatives of the GOP primary will continue forcing Romney to embrace his deely incoherent explanation for his opposition to it in a state with a heavy auto industry presence:

Romney will confront many of the same challenges in Ohio that he faced in Michigan, without the benefit of his hometown connection.

Like Michigan, Ohio’s economy relies heavily on the auto industry, and Romney’s high-profile opposition of the government bailout of the industry is not likely to be received warmly by many voters. He supported an effort last year by Ohio Gov. John Kasich (R) to restrict public unions’ collective-bargaining rights — an effort that was overwhelmingly overturned in the fall by voters in this union-heavy state. And Romney’s courtship of religious voters by supporting, for instance, an antiabortion “personhood initiative,” risks alienating female voters.

“The number one thing is the auto bailout,” said Eric Kearney, a Democrat from Cincinnati and minority leader in the Ohio Senate. “Ohio is the second-largest auto producer in this country. We rely on that. It’s a substantial portion of our economy. The first thing Mitt Romney says, and he repeats it, is he is against the auto bailout. Those are Ohio jobs he’s talking about that he doesn’t want to retain. I don’t get what his strategy is.”

Rick Santorum leads by at least seven points in Ohio; a Romney loss in a state the GOP needs in November will trigger a fresh round of GOP handwringing about Romney’s problem with blue collar whites and all around electability.

Also: As Dan Balz explains, Romney’s win last night will allow him to reset in the state, but the expected closeness of this high-stakes contest is yet another sign that Romney will still be forced to grind his way to victory — not where the frontrunner had hoped to be at this point.

* GOP primary will still drag on for months: No question: Romney is more clearly the favorite for the nomination than he appeared to be 24 hours ago. But now what? Sean Trende has a useful breakdown of the remaining states that illuminates why the contest will likely drag on until May, why the odds of a brokered convention have increased, and why the GOP primary process is far more chaotic than it seems.

* The cost of Romney’s victories: Ross Douthat lays it out: The primary has led Romney to champion a fiscally irresponsible tax plan that will make it hard for him to attack Obama over the deficit, and to commit a series of gaffes that have exacerbated his weaknesses, making a general election win that much harder.

* Super Tuesday won’t be decisive: Peter Hamby explains why the delegate race ensures that the contest will grind on well into the spring.

The larger story: The longer the primary drags on, the more tightly Romney will have to embrace positions that could alienate key swing constituencies in November.

* Romney’s white working class problem, ctd: Jonathan Cohn ferrets out the “familiar class divide” in the Michigan exit polls:

Romney won among voters with a college degree and those making more than $100,000 a year. But he lost (barely) among voters who attended no college and he lost (more substantially) among voters making less than $100,000 a year.

As Cohn notes, this helps explain why Romney didn’t win Michigan — which he should have won resoundingly — as much as he “merely survived it.”

* A political death march: GOP strategist Ron Bonjean gives voice to lingering unease in Republican circles:

“This is going to be a long, drawn-out marathon. It feels like a political death march.”

* Another Medicare battle set in House: Paul Ryan is set to release another version of his Medicare budget soon, and Dems are already launching a preemptive strike by arguing the “premium support” system would increase costs for seniors.

Republicans hope Senator Ron Wyden’s embrace of the plan (the Ryan-Wyden proposal would preserve traditional Medicare as an option) will give them bipartisan cover, but Dems are determined not to let that happen and insist Medicare will loom large in the 2012 elections.

* The price of the Solyndra probe: Politico attempts to tally up the cost in salaries to aides onthe two House GOP panels that have been probing Solyndra: “Combined, those 15 aides from the two panels earned about $1.6 million in salaries in 2011, according to the committees’ expense forms provided to the House Administration Committee.”

* Dems on offense over gas prices? As I reported the other day, with Republicans attacking Dems daily over high gas prices, the DCCC is trying to shift a dynamic in a fight that had them playing defense by stressing the House GOP’s support for Big Oil subsidies.

Now the paid media begins with a new robocall targeting GOP Rep Dan Benishek of Michigan, a preview of the message we’ll be seeing against other vulnerable GOP incumbents.

* Olympia Snow’s huge gift to Dems: Steve Kornacki on Snowe’s retirement: It gives Dems breathing room in very tight contests in Virginia, Massachusetts and elsewere, and gives Dems a precious pickup opportunity that dramatically reduces the odds of GOP control of the Senate.

* And the GOP won’t try to get rid of the filibuster: Kevin Drum makes an interesting case for why Republicans won’t try to nix the filibuster if they take control of the Senate, which, if right, will mean that whoever controls it next year, we’re in for more gridlock and dysfunction.

What else?