Top committee Republican Sen. Orrin Hatch of Utah admitted Congress was partially to blame, but took the former IRS officials to task for what he called "lies of omission" for failing to come clean to lawmakers once it learned certain groups were being targeted.
"We've had some criticism of the Congress because they haven't passed certain laws that would make things clearer – it's also your obligation to come back and tell us," he said.
But even though the IRS scandal has put campaign finance in the crosshairs, reform proponents don't expect the controversy to help their cause.
Sen. John McCain, R-Ariz., who championed the last reform effort to limit outside spending in campaigns, says the latest IRS scandal has left voters skeptical anything can be fixed.
"It has been harmful to the effort in the short term because we have to make sure that the American people will know that any changes we make will not be used in a discriminatory fashion," he says. "It has hurt because it conveys the conception out there that there is an out of control agency and to give them more power and authority would be a terrible mistake."
Lawrence Lessig, a professor at Harvard Law School who supports campaign finance reform, says the easiest solution would be to eliminate the 501(c)(4) designation.
"The core problem is not a bunch of IRS agents in Ohio, the core problem is the law's deep ambiguity and uncertainty about what's a (c)(4) and how do you qualify for a (c)(4)," he says. "This could be simplified radically if you just either eliminated (c)(4)s."
Lessig points out groups that are purely charities already have their own tax-exempt code and political spending groups have their own code as well. The rub is that many political donors, particularly on the Republican side, don't want to give up their anonymity, he says.
"What's obviously happening here is politically there is very little desire, at least among the Republicans, to adopt reforms that further extend the requirements of disclosure," Lessig says.
Meanwhile, a pair of groups filed lawsuits today against the IRS for their discriminatory practices – one was a conservative Texas group that it took more than three years to get its 501(c)(4) application processed and the other was one seeking to compel the IRS to address the differences between law and regulation about what it means to be a social welfare group, filed by Citizens for Responsibility and Ethics in Washington, a pro-campaign finance reform group.
And Lois Lerner, a top IRS official at the heart of the controversy – including the decision to first broach the issue during a private tax panel discussion by planting a question about it in the audience and reading off prepared remarks – is expected to decline to testify under oath before a House committee Wednesday in order to avoid incriminating herself.