Two of South Dakota's congressional delegates are calling for the acting Internal Revenue Service commissioner to be removed or remove himself from his post after recent allegations that the IRS was targeting conservative groups.

Attorney General Eric Holder announced Tuesday that the Justice Department is investigating the allegations against the IRS, which is accused of targeting tea party groups for extra scrutiny when they applied for tax exempt status.

An investigation by the Treasury inspector general found ineffective management at the IRS allowed agents to improperly target tea party groups for more than 18 months. The inspector general's report was released Tuesday. It puts much of the blame on IRS supervisors in Washington who oversaw a group of specialists in Cincinnati who screened applications for tax exempt status.

Now, Republicans Rep. Kristi Noem and Sen. John Thune are calling for the IRS commissioner to be removed from office. Thune issued a news release earlier Thursday calling for IRS Commissioner Steven Miller to resign.

"The report indicates that the abuse of power in targeting certain Americans went on for at least an 18-month period, and any IRS official who knew about this misconduct but remained silent should be fired immediately. For the administration that claimed to be the ‘most transparent in history,' the Obama administration's credibility gap continues to grow at an alarming rate. This sort of breach of public trust is at best the result of incompetence and at worst the result of potentially illegal and malicious conduct," Thune said in a news release.

Noem followed Thune's notion with a news release Wednesday afternoon, saying the power to tax is one of the strongest the government has and it shouldn't be used a political tool.

"The President should take responsibility for his administration and fire the IRS Commissioner. I have cosponsored legislation that will make it a crime to conduct the kind of politically-motivated discrimination we have recently seen from the IRS," Noem said in a news release.

The bill Noem is referring to is called the Taxpayer Nondiscrimination & Protection Act of 2013 would increase the maximum penalty to a $5,000 fine, five years in prison or both.

Sen. Tim Johnson is waiting for the Department of Justice's investigation: 

"Politicization by the IRS is simply unacceptable. Americans expect and demand a neutral IRS. All of those involved need to be held accountable for their wrong doing. DOJ has rightly started a criminal probe, and the Senate is starting hearings so we can get to the bottom of this mess and punish those responsible."

Do you want to sign up for my E-Newsletter?