(CNN) - While the Internal Revenue Service maintains it was not focusing on conservative groups out of political bias, Sen. Rand Paul claimed Sunday there was a "written policy" floating around the agency that said IRS officials were "targeting people who were opposed to the president."
"And when that comes forward, we need to know who wrote the policy and who approved the policy," the Republican senator from Kentucky said on CNN's "State of the Union."
Pressed for more precise details about the memo he was referring to, Paul said he hasn't seen such a policy statement but has heard about it.
"Well, we keep hearing the reports and we have several specifically worded items saying who was being targeted. In fact, one of the bullet points says those who are critical of the president. So I don't know if that comes from a policy, but that's what's being reported in the press and reported orally," he told CNN's chief political correspondent Candy Crowley. "I haven't seen a policy statement, but I think we need to see that."
Senate Minority Leader Mitch McConnell also said the IRS targeting was an example of the administration punishing its opponents.
"There is a culture of intimidation throughout the administration," he said Sunday on NBC's "Meet the Press."
While he admitted that all the facts were not yet known, he argued an attitude of "government knows best” seems to permeate.
"The nanny state is here to tell us all what to do and if you start criticizing, you get targeted," he said.
Appearing before a congressional committee Friday, IRS officials said a large increase in workload, rather than deliberate targeting, led to "foolish mistakes" and the political discrimination cited by the inspector general's report last week.
Numerous conservative groups said they faced heavy scrutiny and lengthy questionnaires in the past few years as they attempted to get tax-exempt status. The IRS admitted earlier this month it made mistakes, saying its office in Ohio that processed tax-exempt applications began singling out groups whose names included "tea party" and "patriot" for further review.
The actions have spurred criticism from both parties in Congress and President Barack Obama. A new CNN/ORC International survey released Sunday indicated that 71% of Americans find the targeting unacceptable.
Two IRS officials have announced they'll leave their posts, and more current and former IRS higher-ups are slated to appear for congressional hearings this week.
But Paul argued more people needed to be let go, saying the Obama administration didn't do enough in disciplining officials after the terror attack against a U.S. diplomatic post in Benghazi, Libya, in September.
"Why does Benghazi go on? No one was ever fired. So people made tragic errors - no one's accepting responsibility and no one was fired," he said.
Four State Department officials, however, were disciplined in December, with one resigning and three being placed on administrative leave and relieved of their duties. Former Secretary of State Hillary Clinton repeatedly said she accepts ultimate responsibility for the safety and security of U.S. diplomats abroad.
Paul, however, stood by his charge that Clinton demonstrated a "dereliction of duty" by not reading diplomatic cables requesting more security at the Benghazi post.
"She should have resigned and accepted blame for it," he said Sunday.
A potential 2016 contender for the Republican presidential nomination, Paul has taken his attacks against Clinton on the road in battleground states. He plans to make a trip to New Hampshire, the first-in-the-nation primary state, on Monday.
Asked if he was politicizing the controversy, Paul said he brings up the topic "in every state and every stop because I think it's pretty important for her to accept blame for not providing security."
Watch State of the Union with Candy Crowley Sundays at 9am ET. For the latest from State of the Union click here.