The list was released as part of a class action lawsuit.
Ribble cited a desire to spend more time with his family and return to the private sector.
But the IRS chief says that's a verdict for investigators to make.
GOP lawmakers fuming about the status of the IRS investigation.
The administration faces pressure to hand over 2,500 documents.
OPINION | Labrador is uniquely positioned in the debate.
Rep. Curt Clawson (R-Fla.) framed the Tea Party as an inclusive movement.
A Treasury watchdog may have found up to 30,000 emails to or from Lerner.
Joe Carr, who lost to Sen. Lamar Alexander (R), is taking on party chairman Chris Devaney.
A Tea Party group is criticizing Yellen's meeing with Obama ahead of the midterms.
OPINION | Tensions between the Tea Party and GOP centrists aren't going away.
A judge said McDaniel waited too long to file a challenge to Sen. Cochran's win.
Senate colleagues rebuffed Mike Lee at a private GOP meeting.
Rep. Mick Mulvaney (R-S.C.) lauded the new regime of Speaker Paul Ryan.
An aggressive lobbying effort by conservatives is seen as a positive sign for TPA.
Anti-government sentiments threaten the very fabric of the American social compact.
The likely 2016 presidential candidate has been reaching across the aisle.
The GOP senator predicted his Arizona colleague would be "just fine" in a potential primary.
Tea Party Express said he would focus on "economic liberty and individual opportunity."
Even the House Speaker's staunchest critics plan to back the GOP leader for another term.
Establishment Republicans crow that resounding wins on Tuesday repudiated conservatives.
Republicans aren't running on a clear-cut agenda, so the path after victory is unclear.
Conservative leaders are meeting to decide whether to go to bat for Sen. Pat Roberts (R).
Conservatives are eyeing a November clash to get their pick past the GOP primary favorite.