Clinton is retiring from her position in President Obama's Cabinet, and has tried to temper expectations that she'd be open to running in 2016. However, after failing to gain the nomination in 2008, her performance as secretary of State has boosted her profile, and many in both parties believe she would be a formidable presidential candidate.
In December, former Speaker and presidential candidate Newt Gingrich (R) said the Republican Party in its current form was “incapable” of beating her if she's the Democratic nominee in 2016.
On the Republican side, the field is far more competitive. Rubio leads with 21 percent support, followed by former vice presidential candidate Rep. Paul RyanPaul RyanRyan secures big win with bipartisan Puerto Rico deal GOP mired in Zika dispute GOP duo unveils healthcare bill maintaining parts of ObamaCare MORE (R-Wis.) at 16. Former Arkansas Gov. Mike Huckabee holds 15 percent support, with New Jersey Gov. Chris Christie and former Florida Gov. Jeb Bush tied at 14, Sen. Rand PaulRand Paul 5 takeaways from the rush for campaign cash Paul calls for end of gun-free zones The Hill's 12:30 Report MORE (R-Ky.) at 5, Louisiana Gov. Bobby Jindal at 3, and Govs. Rick Perry (Texas) and Susana Martinez (New Mexico) each taking 2.
Rubio's recent schedule — a stop in Iowa, the first caucus state, and a high-profile interview with GQ magazine — has many Republicans hopeful that he's gearing up for a run.
However, Clinton trounces Rubio, Ryan and Bush in head to head match-ups, according to the early PPP survey, besting each by 14 percentage points.
The most competitive Republican against Clinton right now is Christie, according to the poll, who trails Clinton 44 to 42.
But Christie has infuriated some on the right recently after praising Obama for the federal response to Hurricane Sandy in the final days of the 2012 campaign, and then bashing congressional Republicans after Speaker John BoehnerJohn BoehnerRyan secures big win with bipartisan Puerto Rico deal John Feehery: GOP: Listen to Reince House GOP budget 'SWAT' team is formed MORE (R-Ohio) pulled a vote on a bill to provide aid to victims of the storm.
Christie's favorability with Republican voters is among the lowest of any of the candidates at 44 positive and 29 negative.