With three lawmakers vying for House majority leader, the battle is coming down to which one can persuade his Republican colleagues that he can lift the cloud of corruption threatening GOP control of Congress in midterm elections.
Until this week, it looked as if acting majority leader Roy Blunt (R) of Missouri may have had the votes to lock up the race.
But a surprise endorsement on Thursday by Rep. Mike Pence (R) of Indiana, who heads the Republican Study Group, the largest group in the GOP caucus, also signaled that key conservative votes are in play - and that reform will be a key theme.
"John Shadegg is a son of the Republican revolution, a member of the fabled class of 1994, and a leader who has never lost his zeal for reform," said Mr. Pence in his statement endorsing the Arizona Republican. He "knows what fiscal and moral reforms are necessary to restore public confidence in the integrity of our national legislature."
Minutes after the Pence announcement, Mr. Blunt's two opponents - Reps. Shadegg and John Boehner of Ohio - called on Mr. Blunt to debate the issues threatening the party's majority.
"It's unfortunate that at a time when House Republicans are having a serious conversation about our future, the candidate who claims to be the frontrunner has so far refused to engage in a debate about how we will reform the House and change the status quo," they said in a statement.
With members scattered across their districts and beyond - and vote pledges in congressional leadership races notoriously unreliable - no count is sure, especially as the battle over reform gains momentum.
In an event in the Great Hall of the Library of Congress, House and Senate Democrats on Wednesday launched a broad plan to curb favors from lobbyists and require more openness in government. Democrats are making the Republicans' ethics woes the centerpiece of their fall campaign, even as Republicans did in the run-up to 1994 elections where they wrested the House from Democrats for the first time in more than 40 years.
Even before Democrats ramped up attacks this week, House Republicans launched their own ethical arms race, with proposals ranging from insulating Congress from lobbyist favors to refocusing on shrinking government - a bid to dry up incentives for corruption.
All plans favor some combination of gift and travel bans and limits on the revolving door between Congress and big lobby firms on Washington's K Street. But an emerging issue in the reform debate is whether Congress will also reform how it does business by eliminating congressional earmarks - the practice of setting aside funds for specified projects or locations, often in representatives' districts.
"If government continues to do things with enormous effects on business, they'll just find another way to protect their interests. There's too much at stake to walk away," says Michael Franc, vice president for government relations at the Heritage Foundation.
Since Republicans took back control of the House, the number of earmarks on spending bills has soared from 1,439 to nearly 14,000, according to Citizens Against Government Waste. Over the same period, the number of lobbyists has jumped from 10,798 to 30,402, many of whom now specialize in obtaining earmarks in spending bills for their clients.
Republicans are divided on how aggressively to go after earmarks in their anticorruption drive. Boehner and Shadegg favor a ban on earmarks; Blunt favors only making the practice more transparent.
"That is an aspect that must be addressed if we are going to cure the illness which has caused this ongoing scandal and an erosion of public confidence in the way that we do business here in our nation's capital," said Sen. John McCain (R) of Arizona, a longtime opponent of congressional earmarks.
Republicans had hoped to head into fall midterm elections running on their legislative record. But the indictment and resignation of House majority leader Tom DeLay and, more ominously, plea agreements of former lobbyist Jack Abramoff and aide Michael Scanlon, including pledges to cooperate with corruption investigations on Capitol Hill, have thrown the GOP back on the defensive.
"We don't just need new leaders, but a course correction," added Rep. Jeff Flake (R) of Arizona, a leading fiscal conservative in the GOP caucus.