Jessica Ebelhar, Associated Press
Nevada Gov. Brian Sandoval addresses the Nevada Development Authority at the Bellagio hotel-casino in Las Vegas Thursday, Nov. 17, 2011. Sandoval said he has helped set Nevada on the path toward recovery by directing his administration to focus on economic development.

Last week the Gallup organization released numbers showing President Obama running about even — 43 percent to 42 percent — with a generic Republican candidate. While the numbers have fluctuated over the last few months, they have been consistently close, suggesting the 2012 presidential race likely will be a nailbiter.

Talking about vice presidential candidates before the GOP has a presidential nominee feels a bit like putting the cart before the horse, but in a close presidential race a good vice presidential candidate can deliver an additional 1 percent to 2 percent of the vote to their running mate, according to a 2010 report in Presidential Studies Quarterly.

When presidential elections are as close as 2012 is shaping up to be, 1 percent can be decisive.

Just ask Al Gore.

"If the eventual GOP nominee is going to unseat Obama," wrote the authors of the political blog The Daily Caller, "he or she will need a running mate who can make inroads with large groups of voters. Of particular interest are women, Hispanics and independents, especially in the battleground states of Florida, Colorado, Nevada and New Mexico."

So who fits the bill for a Republican Party seeking a boost?

Marco Rubio: The junior senator from Florida has strong Hispanic ties, a good relationship with seniors and a high approval rating in a key swing state. Susana Martinez: A tough-on-crime politician who can help a presidential nominee make inroads with women and Hispanics.

Brian Sandoval: This Nevada governor comes from a key western state, has Hispanic connections and a strong anti-crime background.

Nikki Haley: A daughter of Indian immigrants, as governor of South Carolina she practices conservative fiscal principles and has balanced her state's budget.

But GOP presidential hopefuls aren't the only one's weighing their vice presidential options. President Obama might tip the scales in his favor by asking current secretary of state Hilary Clinton to be his running mate, according to the American Prospect, "Recent surveys put her approval ratings in the high 60s, considerably higher than Biden or Obama's himself." They continue, "her strength among women, Latinos and Jews could be of particular value in 2012."