Tea Party-backed candidates suffered more setbacks in Tuesday’s primaries as Republican Senate leader Mitch McConnell easily beat back a once-threatening primary challenge in Kentucky and two conservative firebrands failed to advance to a Senate runoff in Georgia. The eventual outcomes in both states are crucial to the GOP’s hopes of winning control of the U.S. Senate in the fall, but the party in 2014 continues to nominate candidates viewed by mainstream Republicans as having the best chance of winning in November.
Republican establishment candidates, backed by ad spending from groups like the Chamber of Commerce and the American Crossroads Super PAC, have avoided the kinds of high-profile upsets that led to general election losses in winnable states in 2010 and 2012. Earlier this year, establishment-backed candidates defeated Tea Party challengers in Senate races in North Carolina and Texas, with similar contests in South Carolina and Mississippi still to come.
The GOP needs to hold their current seats and pick up six more in largely friendly states to gain control of the Senate. And while both Kentucky and Georgia will be hotly contested general election races in November, the GOP retains a realistic shot at a big fall victory.
Here’s a rundown of Tuesday’s results in the six states holding primaries:
KENTUCKY
Senate Minority Leader Mitch McConnell easily defeated Tea Party challenger Matt Bevin in a Republican primary challenge that failed to live up to its early hype.
Bevin was originally viewed as a legitimate challenger to McConnell in a race symbolic of the GOP infighting establishment Republicans feared could weaken the party’s chances to take back the Senate. McConnell’s campaign worked aggressively to characterize Bevin as hypocritical on fiscal issues, and the top senator was aided by backing from fellow Kentuckian Sen. Rand Paul. Bevin’s campaign stumbled out of the gate and failed to convincingly paint McConnell as weak on conservative issues; his attendance at a rally to legalize cockfighting further derailed his campaign.
McConnell now faces a much stiffer challenge from Democrat Alison Lundergan Grimes, who also won her party’s nomination Tuesday. The contest will likely be November’s marquee Senate race and could decide which party has control of the upper chamber come 2015.
GEORGIA
Two Tea Party candidates faltered in the Republican primary for Senate, while Democrat Michelle Nunn skated to the nomination in a bid to replace retiring Republican Sen. Saxby Chambliss.
Former Dollar General CEO David Perdue emerged as the top vote getter in the crowded Republican field, with Rep. Jack Kingston finishing second. Reps. Paul Broun and Phil Gingrey, along with former Georgia Secretary of State Karen Handel were also vying for the seat.
The two tea party candidates, Broun and Gingrey, did not finish near the top, a relief to Republicans who feared nominating the far right conservatives would hurt the party’s chances to keep the seat.
Because no candidate was able to top the 50 percent threshold, Perdue will face Kingston in a runoff on July 22.
The Peach State’s changing demographics have Democrats hopeful Nunn could win the historically Republican seat.
Democratic state Sen. Jason Carter, grandson of former President Jimmy Carter, also secured the party nomination for governor. He will face incumbent GOP Gov. Nathan Deal.
PENNSYLVANIA
Democrats chose businessman Tom Wolf to square off against unpopular incumbent Republican Gov. Tom Corbett in the fall. Wolf won with deep pockets and an aggressive ad campaign to introduce himself to voters. Rep. Allyson Schwartz was considered an early favorite among DC insiders, but she faded in past weeks. Other candidates were former state environmental chief Kathleen McGinty and state treasurer Rob McCord.
Another high-profile race down the ballot was the unsuccessful bid of former congresswoman Marjorie Margolies, who received national attention after Bill and Hillary Clinton offered their support.
The Clinton nods came because of family ties; Margolies’ son is married to Chelsea. The former one-term House member came up short against state Rep. Brendan Boyle.
OREGON
Republicans hope GOP Senate nominee Monica Wehby will be their ticket to general election victory in this blue state. Wehby, a pediatric neurosurgeon, easily defeated her nearest challenger, state Rep. Jason Conger.
Two separate reports about Wehby’s tumultuous relationships with an ex-husband and an ex-boyfriend could hurt her chances, although in this all-mail-ballot state, many votes were already cast when the damaging news stories broke.
Conger had the backing of influential conservative groups angered by Wehby’s stance that abortion is “a personal decision between a woman and her family.”
Wehby faces Democrat Jeff Merkley in November.
IDAHO
Incumbent Rep. Mike Simpson is another establishment Republican who survived a tea party challenge. Conservative groups like the Club for Growth took aim at Simpson by supporting his opponent, Bryan Smith.
But the Chamber of Commerce and former Republican presidential nominee Mitt Romney helped combat the outside spending and gave Simpson a comfortable primary victory.
Incumbent Republican Gov. Butch Otter won the gubernatorial nomination following a tight race with Republican Sen. Russell M. Fulcher, according to The Associated Press.
ARKANSAS
Neither Democrat Mark Pryor nor Republican Tom Cotton faced a primary challenge ahead of their high-profile Senate race this November.
Former Rep. Asa Hutchinson coasted in the GOP gubernatorial primary, and former Democratic Rep. Mike Ross snagged his party’s nomination as well.
Former Rep. Tim Griffin was the only Republican running for lieutenant governor.
-- NBC's Mark Murray contributed to this report.