The disparate messages may have become muddled for voters.
"The Republican groups could have made a difference," said Bill Burton, whose pro-Obama super PAC, Priorities USA Action, spent about $67 million on ads. "Instead they blew through money with discordant messages and an erratic spending strategy."
Tim Phillips, president of Americans for Prosperity, defended the groups' emphasis on TV advertising in the 2012 election.
But he said Republicans need to recruit better candidates up and down the ballot and make structural changes such as improving their field operations to boost their chances in future races
"We need a deeper, stronger bench and we need to better message our issues and principles. The Romney campaign should have done this and outside groups should have done this," Phillips said.
Fred Wertheimer, a longtime campaign finance reform advocate, predicted that super PACs and other outside groups would be back with a vengeance.
"Some millionaires and billionaires will throw up their hands as a result of this election and say, 'I don't want to do this.' But other people with an interest in government decisions aren't going to walk away from the corrupting influence this system provides," Wertheimer said.
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