Portman: 'I have not' heard from Romney lately

On Tuesday, the Romney campaign announced it hired staff for the the GOP candidate's future running mate, further fueling speculation that the presidential hopeful will announce his pick soon.

Randy Bumps, the former political director of the National Republican Senatorial Committee, will serve as the director of operations for the eventual vice presidential pick. And Kevin Sheridan, a former spokesman for the Republican National Committee, will serve as the running mate's communications director.

But Monday, the Romney campaign flatly denied a report in The New York Times that the GOP hopeful had already chosen his running mate.

"No decision's been made on VP," Romney adviser Eric Fehrnstrom told reporters in Louisiana.