Washington (CNN) -- A gaffe is when a politician is caught telling the truth, the old saying goes.
So it was in March when a hot microphone picked up President Barack Obama telling his Russian counterpart, Dmitri Medvedev, that he will have "more flexibility" if he wins re-election in November.
The president's top aides scrambled to downplay the remark, assuring reporters Obama doesn't have any surprises up his sleeve should voters hand him a second term. But underlying the president's comment is a truism of American politics: Without the specter of a looming election, a second-term president is liberated to pursue policies that aren't politically tenable at the ballot box.
What's more, an Obama win in November would provide an opportunity for the president to claim a mandate to press forward full-throttle with policies Republicans have spent the last two years deriding.
"He's going to try to pick up everything he didn't get the first term and he will certainly try to use whatever mandate he has going forward," said Jennifer Rubin, a conservative columnist for the Washington Post.
Moreover, an Obama win would be a stinging defeat for Republicans who currently view the president as extremely vulnerable. The result may be a rethinking among GOP ranks on Capitol Hill about how to proceed.
"Republicans will be under a huge amount of pressure to be conciliatory," said Rubin.
The last two presidents are instructive: Upon winning re-election narrowly in 2004, President Bush declared that he had "earned political capital." He spent the following months attempting to shepherd through an unpopular overhaul of Social Security, a measure so unpalatable that members of his own party forced him to drop it.
After his easy re-election in 1996, Bill Clinton immediately proposed a massively priced children's health insurance bill and a significant increase in education spending (he got both).
So when Vice President Joe Biden said over the weekend that he supports same-sex marriage -- a position the president has inched steadily toward but not yet backed full-bore -- conservatives and political observers alike took it as a sure sign Obama himself will embrace the issue if his next four years are secured.
"If you ask me, his position is a lot like what he said to Medvedev at the open mic in Europe," said former New York Gov. George Pataki on Tuesday. "I think the American people deserve to know today where President Obama stands today and where he will stand next year on this issue."
So what else do Republicans think may result from an unbridled Obama?
Many Republicans CNN spoke with pointed to taxes first. The president himself has made no secret he wants to raise taxes on American households making more than $250,000 a year. But some Republicans fear that's just the beginning.
"Eventually the structural budget and deficit will have to get addressed, and his solution is likely to be a tax increase on the middle class," Rubin said.
The White House maintains Obama wants to overhaul the tax code, keeping rates steady for middle- and lower-income Americans while closing corporate loopholes and instituting a minimum tax on those making more than $1 million. But Obama has offered few details on the dazzlingly complex undertaking.
"There is uncertainty around the president's tax policy that scares fiscal conservatives" said Margaret Hoover, a conservative commentator who worked in the Bush White House.
"He has to deal with taxes right away and he doesn't know how he's going to do it," said Brad Dayspring, a former aide to House Minority Leader Eric Cantor.
Republicans also predict a massive increase in spending should the president get a second term, starting with health care. Many of the law's reforms don't kick in until 2013, promising a hefty price next year if the measure isn't modified.
"Right now there are just budget gimmicks to pay for it," said Dayspring, "He has to figure out how to pay for it. And he's shown no will to reform entitlements."
"There is a sincere fear that our economy will collapse if Obama stays in office because of spending and entitlements," added Matt Lewis, a conservative blogger for The Daily Caller.
Uncertainty over business regulations is also causing unease. Republicans argue one of the reasons the recovery has been so sluggish is the uncertainty around increased regulations. Presumptive Republican presidential nominee Mitt Romney has vowed to repeal the Dodd-Frank Act, the Wall Street reform measure signed into law by Obama in 2010. Particularly irksome is that the bill bestowed considerable power to rule-making agencies, like the newly established Consumer Financial Protection Bureau.
Should Obama win, he's likely to leave the act untouched.
"Republicans worry that not amending certain provisions of Dodd-Frank will stall the recovery," Hoover said.
On the foreign policy front, critics say Obama could go soft on missile defense in Europe and allow Iran to strengthen its stature.
"Iran and Russia will continue to be emboldened," said Hoover.
Of course, these doomsday scenarios are to be expected in election year politics and the president himself makes similarly unsettling predictions about what a Romney presidency would bring. Meanwhile, White House aides say climate change, energy reform and an immigration overhaul are on the top of the president's list for term No. 2.
But one issue in particular has some conservatives especially wary: the Supreme Court. With three justices well into their 70s, it's likely there will be at least one retirement in the next four years on the high court, possibly from the conservative bloc.
"This is what many Republican thought-leaders are most concerned about," said Lewis. "They have lifetime appointments. It's the most powerful way Obama can leave his mark."