The man who resigned amidst scandal as the head of the Internal Revenue Service last week will appear this morning before the U.S. Senate Finance Committee. Iowa Senator Chuck Grassley wants Steven Miller to explain how the tax collection agency ended up targeting conservative political groups for such close scrutiny.

“I want records of communication on the issue between the Internal Revenue Service and the White House or any other organization in government,” Grassley says. “It’s part of getting to the bottom of how targeting came about and how it was handled inside the administration.”

The IRS is the focus of a Congressional investigation after it was revealed the agency was inappropriately singling out conservative organizations, including tea party activists and anti-abortion groups, for special probes about their tax-exempt status.

“The IRS is the most-feared federal agency and this situation builds on public mistrust,” Grassley says, “especially as the IRS will have even more power starting in January because a big part of its job is going to be enforcing the new health care law.” Grassley, a Republican, says he also wants to question Miller and others to learn what President Obama knew about the situation and when.

“The president might not have been well-served by his aides who didn’t tell him about the situation right away,” Grassley says. “That also then raises questions of what else the White House chief of staff and counsel are keeping from the president and why the president is running the White House in the way that allows this sort of non-communication to happen.”

Grassley says members of Congress have been asking about the IRS’ targeting for more than a year and got no response.

Iowa Senator Chuck Grassley says two big stories out of Washington, D.C. in the past few days show the federal government is becoming “a threat to freedom and liberties.” In one instance, the Internal Revenue Service has admitted targeting conservative political groups with ties to the Tea Party or that had “patriot” in their names.

“There needs to be full accounting from the agency, including details of who was involved,” Grassley says, “An IRS official publicly stated last Friday that the agency had targeted certain groups after the IRS denied this kind of Nixonian activity last year.”

Grassley, a Republican, says he’s heard at countless town meetings in Iowa how people don’t trust the federal government and speak out about it getting bigger and more powerful.

“Now the fact that the IRS was targeting certain groups for political reasons crystallizes the distrust in a very big way,” Grassley says, “because of the IRS’ reach into taxpayer information and the intimidation that comes from the agency.”

It’s also reported the U.S. Justice Department dug into two months of Associated Press reporters’ and editors’ work and personal phone records. Grassley says that’s equally as distressing.

“The Constitution was written not to power government over people but to protect the people from the government,” Grassley says. “When government exercises power that goes beyond the Constitution, it becomes a real threat.”

Not only were the government’s actions unconstitutional, Grassley says, “but it’s a threat to the freedom and liberties guaranteed to the people by the Constitution.”