The political scientists tell us to ignore head-to-head polling at this stage, because it’s far too early for it to have any predictive meaning. That said, a new USA Today/Gallup poll finding that Obama has opened up a huge lead over Mitt Romney among women is noteworthy, because it foreshadows what will be a major subplot in Campaign 2012.

The poll finds that Obama has opened up a significant lead over Romney, 51-42, among registered voters in a dozen swing states — a lead that’s fueled by female voters. Obama leads among women by 18 points — more than offsetting Romney’s small edge among men. The biggest shift has come among women under 50: Obama now leads Romney among them by two to one.

Is the GOP’s sharp right turn back on to culture war turf the explanation? In recent months, we’ve seen battles over the Blunt amendment; over Planned Parenthood; and over Rush Limbaugh’s “slut” comments. And we’ve also seen a GOP primary that has forced the expected GOP nominee to embrace cultural positions that could alienate women and other swing constituencies.

Steve Kornacki notes an interesting parallel to Bill Clinton’s reelection, which also turned heavily on the female vote:

This may be a case of history repeating itself. The last Democratic president to stand for reelection, Bill Clinton in 1996, owed his reelection to a massive and decisive gender gap. His campaign against Bob Dole is generally remembered as a sleepy, suspense-less affair, one that Clinton led wire-to-wire and ended up winning by a healthy eight-point margin. And yet, among men, Clinton actually lost to Dole by a point, 44 to 43 percent. It was women, who sided with Clinton by 16 points, who accounted for his lopsided victory.... with Obama, his presidency provoked relentless, culturally-fueled conservative opposition that had particular resonance with white male voters, especially in the South and rural areas....

Meanwhile, though, Clinton increased his share of the women’s vote by ten points. There was no obviously gender- based issue like contraception to account for this, but it seemed that women reacted with particular hostility to the GOP Congress that was elected in ’94 and to the face of that “Republican revolution,” House Speaker Newt Gingrich..

Clinton also drew a hard line against GOP efforts to cut Medicare, which is also a major issue this year, thanks to the Paul Ryan budget.

I continue to believe Romney will be granted the presumption of moderation once he becomes the nominee, partly because no one really believes he’s seriously committed to cultural issues, and partly because the “radical” or “extreme” label is ascribed to politicians based on cultural issues and tone, and not based on their economic worldview, one area where Romney does hold sincere and heartfelt views that are genuinely radical. And Romney will certainly have a chance to reintroduce himself to core swing constituencies — women included — once he’s the nominee.

But Dems will work hard to remind women of Romney’s positions during the primaries, and this will be a key battlefield, given the expected importance of independent and suburban women to the outcome.

* Mitt Romney’s women problem, ctd.: Chris Cillizza and Aaron Blake also dig into the new polling and argue it was likely caused by a backlash against the GOP over the contraception fight.

* Ann Romney, secret weapon? With the new polling spotlighting Romney’s women problem, Politico gets inside the Romney campaign’s deliberations over how extensively to use Ann Romney as a campaign trail weapon.

Key question: Will she be able to persuade female voters to overlook Romney’s actual positions on issues of importance to them?

* Dems go on offense over Ryan Medicare budget: AFSCME and Americans United for Change are going up with new ads targeting a handful of House GOPers over Medicare. The version targeting Rep. Sean Duffy of Wisconsin is right here; it argues that this year’s plan is no different from last year’s, by stressing that Ryancare 2.0 would end the Medicare guarantee — the central Dem message this year.

Dems hope the Medicare battles will be central to exacerbating the gender gap, as Medicare may have been during the Clinton years.

* GOP doubles down on Paul Ryan’s “fraudulent” budget: As Paul Krugman notes, the key point about the Paul Ryan budget is not just that it doesn’t bother telling you how it would reduce the deficit — even though we keep being told how Very Serious Ryan is. It’s that the Republican Party has doubled down on the larger vision and ideology that Ryan’s budget represents, another sign of how far to the right the GOP has moved.

* Mainstream journalists politely ignoring GOP’s new radicalism? E.J. Dionne notes another reason for the hard lurch to the ideological right on display in the Ryan budget and the repeal-Obamacare crusade: By pretending there’s nothing whastoever out of the ordinary about it, mainstream journalists and moderates are enabling it further.

I’d only add this: Now that Obamacare’s demise is a real possibility, when will the press get serious about asking Republicans what they would replace Obamacare with?

* Romney’s contortions on gas prices: NPR digs into Romney’s past positions and finds that Romney used to say some pretty sensible things about how the overreliance on oil should be an important part of the discussion about gas prices.

ICYMI: The Obama-allied Priorities USA Action is up with a new spot hitting back on gas prices in seven swing states, a reminder of how central this issue will be in Campaign 2012.

* What’s really at stake in SCOTUS’s decision: Jeffrey Toobin weighs in with an important piece that games out the consequences, should the Supreme Court overturn Obamacare and in effect assume the role of supra-legislature:

The decision is a great deal more important than its immediate political aftermath. It’s about what the government can do, not just who runs it. If the Court acts in line with the sentiments expressed by the conservatives last week, it could curtail the policymaking options of Congress for a generation. An adverse decision on the Affordable Care Act could even jeopardize the prospects for conservative legislative priorities, like health-insurance vouchers or private retirement accounts in lieu of Social Security. It is simply not the Supreme Court’s business to be making these kinds of judgments. The awesome, and final, powers of the Justices are best exercised sparingly and with restraint. Their normal burdens of interpreting laws are heavy enough. No one expects the Justices to be making health-care policy any more than we expect them to be picking Presidents, which, it may be remembered, is not exactly their strength, either.

What’s really at stake is whether the federal government will be able to proceed with a perfectly reasonable exercise of Congressional power to solve a major national problem afflicting tens of millions of Americans.

* The GOP’s real turnout problem: Trip Gabriel talks to analysts about the true nature of Romney’s difficulty: He’s having trouble energizing the GOP and GOP-leaning urban and surburban voters who are typically swing voters in a general election, which is where the battle with Obama could be decided.

Key caveat: The question is whether lack of enthusiasm for Romney in the primaries will be more than compensated for in the general election by the GOP base’s seething desire to knock the Kenyan Muslim Marxist out of the White House once and for all.

* And Elizabeth Warren, Scott Brown are deadlocked: A new Boston Globe poll finds Brown and Warren statistically tied at 37-35, with a large bloc of voters still undecided, suggesting the race — which could determine control of the Senate — is wide open.

Key findings: A plurality says Warren would do more to help working people, 44-35, and the “Harvard elitist” label isn’t sticking at all — meaning her “class warfare” message might be resonating. Meanwhile, Brown is viewed as more likeable and is not seen as being in lockstep with the national GOP.

What else?