The Republican presidential candidates have spent months throwing out ideas for what they'd do if elected — cut taxes, reform Medicare, roll back regulations, build moon colonies — but President Obama has been rather vague about what he would do if he wins re-election in November. That fuzziness has left Obama's allies to "project their brightest hopes on him," while allowing rivals to warn of second-term plans that "range from dour to near-apocalyptic," say David Fahrenthold and Peter Wallsten in The Washington Post. Here, seven predictions of what Obama might do — or try to do — if voters keep him around through January 2017:

1. Embrace the cause of same-sex marriage
Obama has been "evolving" in his views on gay marriage since at least December 2010, says Max Markham at PolicyMic, but if he's re-elected, he'll have to stop evolving and "unequivocally come out in favor of same-sex marriage." A growing number of powerful Democrats now endorse same-sex marriage laws, and the public is increasingly on board. In his first term, Obama oversaw the repeal of "don't ask, don't tell"; he will "contribute to the repeal of the discriminatory Defense of Marriage Act in his second term."

2. Pass strict new gun laws
It's no surprise that "gun sales have rocketed" as Obama's re-election odds have improved, says Steve Watson at Many gun-loving Americans want to stock up while they can, fearing that Obama "will use a lame duck presidency to fulfill promises to gun control advocates to take a bite out of the Second Amendment." Obama clearly wants four more years to "destroy" the right to bear arms, NRA chief Wayne LaPierre told the Conservative Political Action Conference in February. "All that first-term lip service to gun owners is part of a massive Obama conspiracy to deceive voters."

3. Kill the Bush tax cuts
One of the first issues a re-elected Obama would have to face is the future of the Bush tax cuts, set to expire at the end of 2012, says Noam Schrieber at The Daily Beast. It's no secret that Obama wants to roll back the tax cuts for the wealthiest Americans, while potentially keeping the lower tax rates for families making $250,000 a year or less. But remember, in 2009, Obama briefly flirted with the idea of letting all the tax cuts lapse. And "having been tempted to end all of the Bush tax cuts in 2009, the president would only find the idea more attractive were he to win a second term," especially as the pressure to cut the deficit grows more intense.

4. Champion civil liberties
My swooning predictions that "Obama would be our first civil libertarian president" have been met with "plenty of disappointments," like the TSA "naked body scanners" debacle, says Jeffrey Rosen in The New Republic. "If Obama wins a second term, I hope re-election gives him the freedom to redeem that unfulfilled promise" by appointing committed civil-libertarian judges and federal regulators. He will also need to meet the challenge of protecting both our privacy and free speech rights in an age where "Google and Facebook are in a race to track consumers as ubiquitously as possible."

5. Play defense
As the historian H.W. Brands noted, "every president that history deems great was re-elected, but no second term goes well," says Erica Grieder at The Economist. So let's not expect much from Obama 2.0. "Most likely, the president would focus his energy on protecting the programs that Congress enacted in his first term, namely health care," says presidential historian Julian Zelizer at CNN. He would also likely push narrower, achievable projects like rebuilding infrastructure.

6. Shift to the right
Another possibility, Zelizer says, is that Obama — a "pragmatic centrist to the core" — might hop on the Republican bandwagon on issues like deficit reduction and Social Security reform. The president's critics claim he's a "big-government liberal," but time and time again, Obama has "frustrated liberals by forcing them to accept compromises" with Republicans. With a lame-duck Obama sure to be "more timid than the first term Obama," he may very well "embrace" government-cutting proposals if he thinks they'll win GOP support.

7. He'll only do as much as Congress lets him
If you want to know what Obama would do, look no further than Capitol Hill, says Ezra Klein at The Washington Post. "If Obama wins a second term, he'll do what Congress lets him do." Americans believe the president is a "director of change," but almost everything a president does has to pass Congress. Obama will do more if Democrats are in charge, and a whole lot less if he's saddled with a hostile Republican Congress and low approval ratings.