UPDATED 12:45

WASHINGTON -- Pennsylvania Sen. Pat Toomey, a Republican, said the IRS' added scrutiny on tea party groups appears "completely politically motivated," contradicting statements from IRS officials."

At a Senate hearing today, Toomey pointed in particular to IRS leaders' inability -- or unwillingness -- to say who allowed the tea party targeting to resume even after it had first been stopped.
"We don’t even know who made the decision. How do we know what motivated that decision? And on the face of it it certainly appears that it’s completely politically motivated," Toomey said. He added, "To my knowledge, there was no criteria idenfitying left-of-center organizations."
IRS leaders and some Democrats have said the targeting is wrong, but do not believe it was motivated by politics.

"I think that what happened here was that foolish mistakes were made by people trying" to handle their workload more efficiently, acting IRS Commissioner Steven Miller said earlier in the hearing.  "While intolerable" he said it was a "mistake, and not an act of partisanship."

At the same Senate Finance Committee hearing, New Jersey Sen. Bob Menendez, a Democrat, said the IRS' action singling out tea party groups for increased, invasive scrutiny is "truly offensive to our concept of democracy and I believe it’s not only unacceptable, it's pretty appalling."

Fellow Democratic Sen. Bob Casey, of Pennsylvania, said IRS officials were not sufficiently contrite.
"I wish there was more of a sense of, frankly, of outrage or at least more contrition being demonstrated," Casey told Miller and Douglas Shulman, the former IRS commissioner. "At a minimum a sense of disappointment and contrition as opposed to, 'we didn’t know,' and I think an attitude that only makes the problem worse."
Miller opened his testimony with an apology and later said he takes responsibility for any IRS actions under his watch.
Menendez said the IRS' bias "undermines the government" and citizens' faith that "its institutions will work in a way that is fair and transparent."
He said there is another scandal, though.
The second one, he argued, includes the abuse of tax-exempt status by groups who are labeled "social welfare organizations" but have clear political aims. He singled out Karl Rove's Crossroads GPS, while saying there are others on both sides of the political spectrum.
"There is a reason that you seek a 501(c)(4) status because you can hide your donors and you also have a tax advantage," Menendez said. "I'd like to see what does it cost the American taxpayers in the granting of all of these 501(c)(4)s when they are not being used for social welfare, but are being used in essence for poitical advocacy."
Toomey, though, pushed back on that idea later, defending the existence of political groups that do not have to reveal their donors. Other types political action organizations have to say who funds them.
"Perhaps one of the most important and influential works of political advocacy ever done in the history of the republic were the Federalist Papers, which were written anonymously, under pseudonyms," Toomey said.