Hillary Clinton isn't just considered by top Democrats to be the leading 2016 presidential candidate. Some see her as the only choice.

Jon Vogel, former Democratic National Committee political director, for example, said that other potential candidates are to see what Clinton does before jumping into the primaries.

Vogel and counterpart Mike Shields, the Republican National Committee's chief of staff, are featured in a short video interview from Harvard University's Institute of Politics. Both were asked about their party's 2016 field.

"Really, is there anyone except for Hillary Clinton right now on the Democratic side?" asked Vogel. "I think we're all waiting to see what she is going to do. Outside of that, it seems hard to imagine any other candidates stepping forward at this point."

Shields, meanwhile, said the GOP list is likely to be long. He included Florida Sen. Marco Rubio, New Jersey Gov. Chris Christie, Wisconsin Gov. Scott Walker, Virginia Gov. Bob McDonnell, Louisiana Gov. Bobby Jindal, New Mexico Gov. Susana Martinez, and South Carolina Gov. Nikki Haley. "We almost have an embarrassment of riches," he said. "We have a whole field of Cinderella stories."