Senate Democrats’ inability so far to lure top-tier talent to run for their three most vulnerable open seats shifts the spotlight to recruits in its two most promising pickup opportunities — a relative term in this lopsided landscape.

Former Montana Gov. Brian Schweitzer’s decision this weekend to eschew a Senate race came as an unexpected boon for the GOP’s hopes of netting the six seats necessary to win the Senate majority next year. Pulling off that feat would be an accomplishment for Republicans, even if they are waging war in friendly GOP territory.

But there is a realistic scenario that could force Democrats to rely on two first-time federal candidates in states where the party has enjoyed little success in recent years. If Montana moves off the competitive playing field and Republicans are also favored to pick up the open seats in West Virginia and South Dakota, the GOP would need to pick up just three more seats from their most promising targets in Alaska, Arkansas, Iowa, Louisiana and North Carolina.
Such a scenario would give Democrats further incentive to alter the math by investing in the only two Republican seats the party appears to have a  chance to win.

“Kentucky and Georgia represent prime pickup opportunities for Democrats in red states, whereas Republicans have failed to expand the map into any blue or purple states,” Democratic Senatorial Campaign Committee spokesman Justin Barasky said. “Our competitiveness in each makes it increasingly difficult for Republicans to take back the majority.”

Democrats were targeting these two seats even before Schweitzer’s announcement. If Democrats are headed for victory in one of them in the closing weeks of the cycle, Republicans would need to pick up seven seats for the majority — more than they won on Election Day 2010, a wave year for the GOP.

But if Montana proves unwinnable, the Kentucky and Georgia races become must-wins rather than padding.

Democrats are underdogs in both states, but party operatives have reasons for hope; they have recruited two fresh-faced candidates who are untested at the federal level. Kentucky Secretary of State Alison Lundergan Grimes is challenging McConnell, and Points of Light Foundation CEO Michelle Nunn is expected to announce soon whether she will vie for the seat of retiring Sen. Saxby Chambliss, R-Ga.

Meanwhile, Republicans may suffer a recurring headache in the Peach State as crippling issues could arise from a protracted GOP primary and runoff process. Reps. Paul Broun, Phil Gingrey and Jack Kingston are all vying for the GOP nomination. Former Georgia Secretary of State Karen Handel and David Perdue, a wealthy businessman and cousin of former Gov. Sonny Perdue, are also running.

But national Republicans remain skeptical that Democrats can capitalize now on the state’s demographic changes, which are expected to make it a battleground presidential state in the near future.

In Kentucky, a massive fundraising advantage and favorable politics of the state give McConnell the edge. Typically, challenging an incumbent is more difficult than winning an open seat, but Democrats believe Grimes can at the very least give the Republican leader a tough time.

The National Republican Senatorial Committee hopes national Democrats do in fact expend valuable resources in Georgia and Kentucky, thereby steering away funds from GOP targets.

For Republicans to win the majority, they will likely need to defeat at least three of the following four incumbents running in states President Barack Obama lost — Sens. Mark Begich of Alaska, Mark Pryor of Arkansas, Mary L. Landrieu of Louisiana and Kay Hagan of North Carolina, none of whom can be considered likely to lose at this point.

“Instead of protecting Mark Pryor, Mark Begich, Mary Landrieu and Kay Hagan, Senate Democrats instead are preparing to pour tens of millions of dollars into long shot races like Georgia and Kentucky,” NRSC spokesman Brad Dayspring said. “That decision alone will cost one or two of these endangered Democratic incumbents their seats.”

The fields against the four incumbents are still taking shape: Rep. Bill Cassidy is challenging Landrieu; Alaska Lt. Gov. Mead Treadwell is challenging Begich, but he’ll have company in the GOP primary from 2010 nominee Joe Miller and possibly state Natural Resources Commissioner Dan Sullivan; Rep. Tom Cotton is considering a challenge to Pryor; and the NRSC is reportedly still talking with potential candidates in the race against Hagan.

Things could be far worse for Democrats even in this already lopsided landscape, in which they are defending eight of the 10 most competitive seats. Republicans don’t yet have top-tier candidates to take on Democratic incumbents in New Hampshire, Minnesota, Colorado or Virginia — all Senate battlegrounds in recent years.

Democrats’ failure to lure A-list candidates to defend open seats in West Virginia, South Dakota and, now, Montana, puts both the individual seats and the majority at risk. But the party is slightly favored now to win the open seat in Iowa and in even better shape in Michigan.

Will the parties look back next year on Schweitzer’s exit to pinpoint when the landscape was altered?

Republicans certainly think so. In an email to donors on Monday, NRSC Chairman Jerry Moran called it “a sea-change moment in our effort to earn back the Senate Majority.”

DSCC Executive Director Guy Cecil maintained on Saturday that “the overall math still favors Democrats,” adding that the party has recruited “a strong challenger” to McConnell.