Public opinion polls show that former Secretary of State Hillary Clinton is the overwhelming favorite to be the Democratic Party's presidential nominee in 2016, should she decide to run.
There is no clear front-runner among potential candidates for the Republican Party nomination, suggesting a wide open primary battle in two years' time.
Clinton has been a fixture on the national political scene for more than 20 years, as first lady, U.S. senator, presidential candidate and secretary of state. She is expected to decide on a presidential run later this year, and, if she runs, would be a formidable candidate.
"What is quite amazing in the Democratic Party, the president's party, is that there is basically one candidate way ahead of the field and that is Hillary Clinton," said political analyst Stephen Hess.
If she does run, Clinton can expect questions from rivals about her handling of the terrorist attack on the U.S. mission in Benghazi, Libya, in 2012. She recently called the Benghazi attack her biggest regret, though last year she fended off political attacks on her handling of the incident.
"The fact is we had four dead Americans," she said. "Was it because of a protest or was it because of guys out for a walk who decided they would go kill Americans? What difference at this point does it make? It is our job to figure out what happened and do everything we can to prevent it from every happening again. senator."
As a presidential candidate, Clinton could face a challenge from Vice President Joe Biden, who is a distant second in the latest polls. Clinton's status as the clear front-runner has pros and cons, according to Hess.
"If you are way out there, everybody is shooting at you, gunning at your back, not only other possible candidates but certainly the media," he said. "So she is in a very exposed position. On the other hand, [she is in] a very good position in that she is raising a lot of money."
Clinton may have to distance herself from an unpopular President Barack Obama. "She will look for a number of areas where she has differences with the current president, her president, and themes that she addresses that convey a sense that she will be a candidate to bring change," said analyst Stuart Rothenberg.
Republicans have no clear front-runner at the moment, but possible contenders include New Jersey Governor Chris Christie who remains embattled in scandal over a traffic jam orchestrated by his aides.
A Christie stumble could open the way for others including former Florida Governor Jeb Bush, Wisconsin Governor Scott Walker, Texas Senator Ted Cruz and Kentucky Senator Rand Paul.
One of the most intriguing 2016 matchups would pit Hillary Clinton against Jeb Bush, says Hess. "Everyone around the world would have fun with that because they are not familiar with many of the names, as they shouldn't be, of American politicians," he said. "But those are two names that they know very, very well, Bush and Clinton."
The official nominating process will not begin for two more years, but many of those interested in running in 2016 are expected to make a decision by the end of this year.