There will be more hearings this week in the Congress on the IRS targeting of more conservative political groups, as Republicans try to zero in on who signed off on the effort as the GOP presses the Obama Administration for answers.

These hearings come after Friday's first Congressional review of the IRS work on tax exempt applications by a series of Republican-leaning groups, which the IRS internal watchdog found were wrpmgly impeded by tax agents.

"Is this government so drunk on power that it would turn its full force, its full might to harass and intimidate an average American who only wants her voice, and their voices heard?" asked Rep. Kevin Brady (R-TX), as he detailed how one Texas Tea Party leader was dealt with by the IRS after applying for tax exempt status for her group.

"She was visited by the FBI Domestic Terrorism Unit, her personal returns and her business returns were both audited by the IRS; she received four FBI inquiries, and her business received unsolicited audits, unscheduled audits by OSHA, the Commission on Environmental Quality and ATF, twice," Brady said.

It's those type of details - repeated in a number of cases - that have given Republicans a distinct advantage in this debate, because they can point to multiple examples of IRS targeting, and not just make claims that some groups are being harassed.

Those earlier claims were batted down repeatedly at Congressional hearings by IRS officials, several of whom will be before lawmakers this week, and will most certainly be asked about their denials in recent years.

"As you know we pride ourselves on being a non-political, non-partisan organization," said former IRS chief Doug Shulman; he will be grilled at both hearings this week, especially over his flat-out denial in 2012 that any Tea Party groups were targeted.

"There's absolutely no targeting; this is the type of back and forth that happens when people apply for 501(c)(4) status," said Shulman.

Here are the witnesses for this week's IRS hearings:

Tuesday May 21 - Senate Finance Committee

Steve Miller, outgoing Acting IRS Commissioner
Russell George, IRS inspector general
Doug Shulman, former IRS Commissioner

Wednesday May 22 - House Oversight Committee

Neal S. Wolin, Deputy Secretary of Treasury
J. Russell George, IRS inspector general
Lois Lerner, Director of Exempt Organizations, IRS
Douglas Shulman, former IRS Commissioner