Rep. Todd Akin’s decision Tuesday to stay in the Missouri Senate race makes the Republican path to the majority steeper as the Show-Me State is no longer one of the GOP’s strongest pickup opportunities.

Akin made it clear that he has no plans to step aside amid the controversy over remarks he made about rape and pregnancy, despite immense pressure from party leaders across the widest possible swath of the GOP establishment.

Unless Akin changes his mind over the next month – a scenario that looks increasingly difficult – vulnerable Sen. Claire McCaskill (D) will face an opponent without any support from the National Republican Senatorial Committee, Senate leaders and the party’s presidential ticket.

The NRSC on Monday took a very hard line from which it is unlikely to be able to walk back.

“Senator McCaskill knows that the only way she wins re-election is if Todd Akin is her opponent in November,” NRSC Communications Director Brian Walsh said in a statement.

“We continue to hope that Congressman Akin will do the right thing for the values he holds dear, but there should be no mistake – if he continues with this misguided campaign, it will be without the support and resources of the NRSC,” Walsh said.

The whole episode has led GOP consultants to begin to rethink the Senate map and ponder where the next best pickup opportunity might be.

“If I’m [NRSC Chairman] John Cornyn, if I’m Karl Rove, if I’m running the outside groups, I know I have to turn one more seat,” Florida-based GOP strategist Ana Navarro said. “I’m now looking at the map and thinking, ‘Which of these states are the most feasible?'”

Akin’s decision could be a boon for more GOP money moving toward Montana, where Sen. Jon Tester (D) faces a tough challenge from Rep. Denny Rehberg (R). It could also move the open-seat Wisconsin Senate race, where former Gov. Tommy Thompson (R) faces Rep. Tammy Baldwin (D), further up on Republicans’ radar. The GOP-aligned group Crossroads GPS is already spending money on ads in the Badger State.

But the money that the NRSC and its aligned outside groups would have spent in Missouri could be redirected toward making a second-tier race more competitive. Democrats are viewed as having an edge in the Senate contests in Florida, New Mexico and Ohio, but all have the potential to grow more competitive this fall.

The extra resources could make a difference in Florida, especially, because it is such a prohibitively expensive state.

Republican Rep. Connie Mack IV, the son and namesake of a former Florida Senator, is waging an uphill campaign against two-term Sen. Bill Nelson (D).

Navarro explained that the Sunshine State Senate race has recently grown more competitive.

“Florida has moved up in feasibility. It went from no shot in hell turning Republican to now being far more competitive,” she said. “You’re gonna have upwards of $10 million in disposable cash that had been allocated to Missouri that’s going to need a home.”

In addition to the NRSC, American Crossroads, the sister organization of Crossroads GPS, also said it has no plans to spend in Missouri if Akin stays in the race.

Akin, first elected to the House in 2000, is a candidate who has never been a particularly strong fundraiser, especially by the standards of a hard-fought Senate campaign. So it’s a particular blow that he will now run without the national party’s resources or imprimatur.

As for the incumbent, expect the McCaskill campaign to stick to its original anti-Akin playbook, highlighting instances where he is outside Missouri’s mainstream and promoting McCaskill as a moderate, independent voice for the state.

And with Akin’s inflammatory comments about rape on video, McCaskill should have an easy time making that case to voters. Now that he is, in effect, a Republican without a party, Akin is unlikely to have the resources to properly push back.

While the dynamics of the race have shifted significantly in favor of McCaskill over the past few days, Roll Call continues to rate the Missouri race as a Tossup – for now. We’ll reassess our rating as the dust settles from the Akin flap heading into next week’s Republican National Convention.

What we do know is that 76 days is a long time to go before Election Day. And, Missouri is not Delaware, where Republicans wrote off a given Senate pickup opportunity after a fatally flawed candidate won the GOP primary last cycle.  

Missouri remains a conservative state, and McCaskill, who was an early and strong supporter of President Barack Obama, still has weaknesses.

The question is whether Akin on his own, without party support and strategic advice, will have ample resources to exploit them.