This is a year of auditioning, positioning, networking and just plain hard work for people who are considering running for president in 2016. You could see them stirring in 2013 as they plugged holes in resumes, took preliminary steps to build potential campaign organizations and made carefully calibrated moves to become better known by Americans in general and key constituencies in particular. Most but not all are ticking off items on what could be called the presidential prep checklist.

Potential contenders for the Republican and Democratic presidential nomination:

The Democratic Party:

Joe Biden, 72, Democratic Party, US senator from Delaware and current vice president	Hillary Clinton, 67, Democratic Party, former US Secretary of State and US Senator and the wife of former president Bill Clinton
Martin O'Malley, 51, Democratic Party, the 61st and current Governor of Maryland	Andrew Cuomo, 57, Democratic Party, New York State Governor

The Republican Party:

Marco Rubio, 43, Republican Party, US senator from Florida and a member of the Senate Foreign Relations Committee	Bobby Jindal, 43, Republican Party, the 55th and current Governor of Louisiana and the Vice Chairman of the Republican Governors Association
Chris Christie, 52, Republican Party, the 55th Governor of New Jersey	Rick Santorum, 56, Republican Party, US Senator representing Pennsylvania
Ted Cruz, 44, Republican Party, US Senator for the state of Texas	Jeb Bush, 61, Republican Party, the 43rd Governor of Florida from 1999 to 2007 and the second son of former president George H. W. Bush
Paul Ryan, 44, Republican Party, Wisconsin Congressman and Chairman of the House Budget Committee since 2011	Scott Walker, 47, Republican Party, the 45th Governor of Wisconsin
Rick Perry, 64, Republican Party, the 47th and current Governor of Texas	Rand Paul, 51, Republican Party, US Senator for Kentucky