Editor's note: David Gergen is a senior political analyst for CNN and has been an adviser to four presidents. He is a professor of public service and director of the Center for Public Leadership at Harvard University's Kennedy School of Government. Follow him on Twitter: @David_Gergen. Michael Zuckerman, who graduated from Harvard College in 2010, is Gergen's assistant.
(CNN) -- Even as events here in the United States are reshaping the political landscape for the 2012 presidential elections, it has become blazingly clear that what is happening in Europe may actually prove more decisive.
Domestically, there has been a rat-a-tat of events that are raising the odds of Mitt Romney's winning the GOP nomination. Rick Perry's prospects have tumbled repeatedly in recent weeks, with weak debate performances, flagging poll numbers, and, most recently, the revelation by The Washington Post of a racial slur at the gates of a Perry family hunting lodge in West Texas.
The damage from the debates and poll numbers are reversible, but the ranch story may yet leave a more lasting imprint -- and it may give the press more incentive to dig into his Texas past. He may yet emerge intact from that, too, but intense scrutiny can place a candidate in harsh, cruel light. As Robert Penn Warren's Willie Stark insists in "All the King's Men": "There is always something."
As Perry's star fades, it has become even more apparent that he has done a couple of major favors for Romney. First off, Romney is no longer on cruise control -- he is trying harder in his public performances and connecting better. Moreover, coming from Romney's right flank, Perry has made the former Massachusetts governor seem more mainstream. That alone may not win over many delegates at a convention, but it will make Romney seem more electable as time goes on.
The other key domestic event, of course, was New Jersey Gov. Chris Christie's decision not to run. Christie's opt-out not only spared Romney a tough rival with crossover appeal but has also set the field, unlocking many GOP donors still waiting in the wings (several of whom already seem to have come on board to Romney).
Combined with Perry's troubles and flagging polls, we are seemingly back where we started with this race for the GOP nomination: There's Romney and there's everybody else.
All of this is important in shaping the GOP landscape but, in terms of fall 2012, what happens over the next few months in Europe may have an even greater bearing on the outcome.
Since even before James Carville's famous dictum, it's become accepted wisdom that the economy plays a commanding role in the outcome of elections. But, as The Washington Post's Ezra Klein, among others, has recently argued, what's most striking about the current situation is how little power we in America may even have over the course our economy takes in the next 13 months.
As Klein points out, Greece stands on the brink of default -- with Ireland, Portugal, and perhaps even Spain and Italy poised to follow them into the abyss. If the European financial powers, chiefly Angela Merkel's Germany, do not step in to avoid catastrophe, the ensuing collapse would not only swallow the European economy, but ours along with it. Europe is too big an economy and too intertwined a trading partner for us to escape the fallout if they fail.
This Damoclean sword hangs over the country and the Obama presidency in an economic landscape that, even taken in isolation, looks nowhere near rosy. Even if Europe stays afloat, many forecasters -- among them Goldman Sachs, Moody's, Bank of America/Merrill Lynch -- still believe the economy may droop dangerously close to recession in the year ahead.
Coupled with the threat of a widening euro debt crisis, President Barack Obama's prospects look daunting indeed. Fair or not, leaders own the economies they preside over. And while it is easy to call the first plunge a George W. Bush recession, history suggests that, in voters' eyes at least, a second dip would belong chiefly to Obama.
The danger from Europe, of course, is no reason to accept further inaction here at home. Federal Reserve Chairman Ben Bernanke's testimony on Capitol Hill on Tuesday underscored the ongoing frustration with Congress for political gridlock in the face of such serious challenges. On the recent protests on Wall Street, even the staid Bernanke noted they represent a citizenry increasingly "dissatisfied with the policy response in Washington." He continued: "At some level, I can't blame them."
But Bernanke struck a more forlorn note when he faced questions on Europe. The Fed, he answered, was powerless in the face of the widening crisis and the American people, unfortunately, "innocent bystanders" to whatever transpires.
So, too, perhaps, the president's re-election prospects. There is time yet for a turnaround, and hope that the Europeans will summon the political courage -- so sharply lacking stateside -- to do what is necessary. If they don't, we may instead see a stunning irony unfold: a president whose critics tirelessly paint him as seeking to Europeanize America, undone by the very continent he supposedly admires so much.
The opinions expressed are solely those of the authors.