Obama campaign strategist David Axelrod on Thursday said he wasn't surprised that his campaign hadn't raised as much money as Mitt Romney's campaign.

"You pick up all the money that you couldn't raise in the primary from Republicans who were supporting other candidates," Axelrod told CNN's Wolf Blitzer. "So we anticipated this."

Politico has reported that Republican groups like the U.S. Chamber of Commerce, Crossroads GPS and Americans For Prosperity plan to spend approximately $1 billion on November’s elections. The Romney campaign and Republican National Committee plan to raise an additional $800 million.

"We are going to be the first president to be outspent," Axelrod added. "Not because of what Romney is raising, but because of the Super PACs. When you have people like the Koch Brothers, who just were so active in Wisconsin, say they are going to spend $400 million to impact this race, that's more than John McCain and the Republican Party spent in total the last time."

The 2012 elections have already been flooded with outside money thanks to the Supreme Court's 2010 Citizens United ruling, which held that limiting corporate campaign spending violated the First Amendment, because political contributions were a form of political speech. The ruling gave rise to Super PACS, organizations that can raise an unlimited amount of money to influence federal elections.

"That is a source of concern," Axelrod said. "It should be a source of concern to everyone."

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