CHARLOTTE -- Catawba College political professor Dr. Michael Bitzer says there were at least two running mates Republican presidential candidate Mitt Romney could have chosen instead of representative Paul Ryan.

“Ryan was thought to be one of the top contenders but not the top contender,” said Bitzer. “The conservative safe choices would have been Rob Portman from Ohio, Tim Pawlenty from Minnesota, but it looks like Romney was looking to go after the Tea Party base.”

Bitzer calls Ryan a lightening rod. A young, outspoken conservative congressman from Wisconsin who has a knack for economics.

Last January, Ryan publicly sparred with President Obama about the GOP's budget proposal.

Shortly after Ryan was announced as Govenor Romney's running mate, the Obama campaign released this statement:

"As a member of Congress, Ryan rubber stamped the reckless Bush economic policies that exploded our deficit and crashed our economy. Now the Romney-Ryan ticket would take us back by repeating the same, catastrophic mistakes."

Bitzer says Ryan's presence in the presidential race further divides the two candidates. He says it turns the upcoming election from a referendum on President Obama to a choice between two candidates.