Rep. Todd Akin has refused to quit the Senate race in Missouri, despite calls from Republican leaders for him to exit after he made controversial remarks about rape and abortion. (Orlin Wagner/AP)

Republicans have had a long-standing reputation for orderliness and conformity that seemed to make the GOP the more manageable political party, compared with the always fractious Democrats.

But those days are long gone, and Rep. Todd Akin’s defiant refusal to step aside as the party’s Senate nominee in Missouri, despite near-universal condemnation from the Republican brass, is only the latest example of just how much the party’s leadership infrastructure has atrophied — and the problems that presents for new GOP leaders, including Mitt Romney, the presidential nominee-in-waiting.

“This is a good test. We’re hierarchical. We respect authority. It will be interesting to see if our authority has become so disrespected that Akin can stay in the race,” said Ed Rogers, a former Reagan and George H.W. Bush White House adviser who now chairs the Barbour, Griffith, Rogers lobbying firm.

Senior GOP strategists in Missouri and Washington hunkered down Wednesday for what they expect could be a week or more of waiting, first to see if Akin can raise enough money to continue his Senate bid, and then for polls to indicate how much damage the affair has done to their chances of toppling the Democratic incumbent, Sen. Claire McCaskill.

This latest example of fraying party power comes at the worst possible moment for the GOP, highlighting tensions between the Republican establishment and some of the party’s most conservative activists as Romney is about to be crowned the presidential nominee next week in Tampa.

The firestorm erupted Sunday when Akin told a television interviewer in St. Louis that he opposes abortion, even in cases when the pregnancy resulted from rape. “If it’s a legitimate rape, the female body has ways to try to shut that whole thing down,” he said, adding that even if the woman became pregnant, “the punishment ought to be of the rapist and not attacking the child.”

The denunciations came from far and wide, including from Romney, who urged Akin to “consider what course would be in the best interest of our country.” The congressman apologized repeatedly but refused to quit.

Romney’s own influence in the party, already in doubt among some social conservatives because of his moderate stewardship as Massachusetts governor, is also on the line as Akin continues to defy him and the rest of the GOP leadership.

The flare-up also has driven the party off-message at a time when it had hoped to focus the campaign on President Obama’s handling of the economy.

“We’re a pro-life party, but we’re much more focused on getting the economy back on track,” said Nathan Conrad, a spokesman for the Wisconsin Republican Party.

Akin has complicated that message for the GOP this week, forcing Republicans across the country to issue one rejection of him after another.

Not that long ago, both Republicans and Democrats had the kind of party apparatus that had more leverage in choosing candidates and, if something went awry, was more forceful in pushing them aside for more viable alternatives.

In 2002, Minnesota Republican Tim Pawlenty, then a member of the state House, wanted to run for U.S. Senate. But Vice President Richard B. Cheney called him and ordered him into the governor’s race so that Norm Coleman, then mayor of St. Paul, would have a clear shot at the Senate seat. Both Republicans went on to win that fall.

In recent years, however, with a more diffuse campaign finance structure, national and state party organizations, particularly on the GOP side, have lost some of that clout.

Instead, interest groups have sprung up with fundraising networks that can connect anti-establishment candidates with sources of cash that weren’t available to them just a decade ago.

“Today’s candidate isn’t necessarily beholden to the party,” said former representative Tom Reynolds (N.Y.), a two-term chairman of the National Republican Congressional Committee.

Democrats, for years considered the more disorganized party, have had some of their own cases of political mutiny. In 2010, after then-Sen. Arlen Specter switched parties to become a Democrat, Obama and Pennsylvania’s Democratic establishment strongly endorsed him, only to see him lose in the primary to Joe Sestak, a congressman from the Philadelphia suburbs who lost the general election.

Republicans, however, seem more afflicted by the changes.

A recent example came in Texas, where the state’s entire elected GOP establishment, led by Gov. Rick Perry, lined up behind Lt. Gov. David Dewhurst in the race for an open Senate seat. Dewhurst vastly outspent his primary opponent, Ted Cruz, before the July 31 runoff. But the former state solicitor general had reinforcements from conservative groups such as the Club for Growth, which spent more than $5 million on his victory.

Similar scenarios played out in so many Republican Senate primaries in 2010 — with anti-establishment candidates winning in Utah, Nevada, Kentucky, Colorado, Alaska and Delaware — that the National Republican Senatorial Committee threw up its hands this year and declared that it would not endorse in competitive primaries.

That’s how the Aug. 7 primary in Missouri unfolded. No establishment figure emerged, and three candidates divided up various splinters of the conservative base: The Club for Growth and the U.S. Chamber of Commerce supported businessman John Brunner, Sarah Palin endorsed former state official Sarah Steelman, and Christian evangelical leaders supported Akin.

Since Akin’s “legitimate rape” comment, Romney and GOP leaders have used every public strategy at their disposal to try to force him out of the race, which would allow state Republican officials to select his replacement.

“I have never seen such a strong messaging effort from a party asking a candidate not to run,” Reynolds said. So far, without success.

Akin is betting that an ad campaign he launched Tuesday will help shore up his support and that his campaign will catch on with conservative activists in the same way Cruz’s primary campaign did.

Dick Wadhams, a former chairman of the Colorado Republican Party and a longtime GOP operative, warned that the Akin incident could eventually mirror the way Colorado Republicans lost the 2010 governor’s race, after sparring with the party’s nominee, who had strong tea party support. The nominee then faced questions about his professional past, as well as a late third-party challenge from a conservative, helping elect Democrat John Hickenlooper.

“Sometimes candidates get into their own little world and talk themselves into this notion that they can get past a certain problem that is politically fatal,” Wadhams said.