Republicans' hopes of winning back the Senate received a boost in Tuesday's primary elections, with Minority Leader Mitch McConnell of Kentucky easily winning and other candidates favored by the party establishment poised to beat back Tea Party challengers.
After years of intraparty turmoil that cost Republicans key races, voters this year are coalescing around the GOP's strongest candidates ahead of November's general election, when Senate control during President Barack Obama's final two years in office will be up for grabs.
On Tuesday, the most consequential day of voting so far this year, the fall landscape began to take shape. Unlike in 2010 and 2012, which gave rise to conservative firebrands, Republicans put forward Senate candidates with the potential to appeal to the moderate voters who could determine outcomes in many states. They hope that more reserved and mainstream candidates can capitalize on Mr. Obama's unpopularity and the troubles with his signature health care law.
Nowhere was this more evident than in Kentucky, where Mr. McConnell's weak poll numbers at home and voters' overwhelming dissatisfaction with the Senate he helps lead made him particularly vulnerable to a conservative primary challenger. But after spending years deftly navigating his party and more than $10 million on his primary campaign, Mr. McConnell and his team easily defeated Matt Bevin. Mr. McConnell will now head for a showdown with Democratic nominee Alison Lundergan Grimes, Kentucky's secretary of state, in what could become the year's most expensive Senate race.
"Conservatives are eager to win," said Josh Holmes, a senior McConnell adviser. "People are tired of losing; 2010 stung, and people in our party want electable conservative candidates who can win across the board and compete in the fall. So far, we have a perfect record in these primaries, and that bodes well for the primaries on the horizon."
In Georgia, where Democratic candidate Michelle Nunn's impressive early showing has turned the race for an open Senate seat into one of this year's marquee contests, the most conservative Tea Party candidates have struggled to catch on in a crowded field for Tuesday's Republican Senate primary. The three Georgia candidates who are considered to have the broadest general-election viability -- businessman David Perdue, Rep. Jack Kingston and former Georgia secretary of state Karen Handel -- were leading in the polls before Tuesday's primary. But the race grew caustic in the closing days, and with the top two finishers likely facing a runoff July 22, the coming weeks could be tumultuous and could damage the eventual nominee.
The outcomes in Georgia and Kentucky could complicate the map for Democrats, who view the two states as their best and perhaps only opportunities to win Senate seats held by Republicans.
Democrats had hoped that Mr. McConnell would emerge from his primary challenge badly bruised, if not defeated, but he appears to be largely unscathed. And in Georgia, Democrats were banking on Republicans nominating a candidate so far to the right that he or she alienates suburban centrist voters who are critical to any winning coalition. But with Mr. Kingston, Mr. Perdue or Ms. Handel atop the GOP ticket, Ms. Nunn's path to victory would be more difficult.
In recent election cycles, Republicans have nominated several flawed conservative candidates -- including Sharron Angle in Nevada and Christine O'Donnell in Delaware in 2010, and Todd Akin in Missouri and Richard Mourdock in Indiana in 2012 -- who made mistakes and lost races that Republicans were within reach of winning.
"If people were expecting history to repeat itself, where you have extreme and underfunded candidates get through -- it doesn't happen a lot," said strategist J.B. Poersch, who ran the Democratic Senatorial Campaign Committee in its successful 2006, 2008 and 2010 cycles.
In all six states holding primaries Tuesday, the differences between Republican candidates were more stylistic and rhetorical than ideological. The contrasts were not over policy and positions, but over how they would legislate on Capitol Hill and how combative Republicans should be with Mr. Obama and Democratic lawmakers. Leaders of conservative groups argued that this was evidence of establishment candidates adopting Tea Party principles, not of a diminished Tea Party movement.
"Everybody runs like a Tea Party candidate now," said Matt Kibbe, president of FreedomWorks, a group that funds Tea Party activities. "Everybody is running against Obamacare and against overspending in Washington. It wasn't always like that with the Republican establishment. I don't even recognize McConnell from where he was a few years ago."
Being prepared financially and politically to handle the volatility within the party's base has been critical this year for GOP incumbents. "No one is being caught flat-footed anymore," said former Rep. Steven LaTourette, R-Ohio, who heads the centrist Main Street Partnership. "The establishment is ponying up resources, and Republicans are generally starting to get behind some people who would like to see their government work. Tuesday should be a wake-up call to Democrats that Republicans are going to dig in and make a real play for the Senate majority."
This looked to be the case from coast to coast. In Oregon, Monica Wehby, a well-funded pediatric neurosurgeon, was favored to win the Republican Senate nomination over her more conservative challengers, potentially putting the seat held by Democratic Sen. Jeff Merkley in play.
In Idaho, home to one of the most hotly contested House GOP primaries, Rep. Mike Simpson appeared headed toward victory over Bryan Smith, who was backed by conservative organizations. Mr. Simpson, an ally of House Speaker John Boehner, R-Ohio, came under attack for his vote for the 2008 bank bailout known as the Troubled Asset Relief Program. But with support from the U.S. Chamber of Commerce and other mainstream GOP groups, he minimized Mr. Smith's ascent.
The Tea Party's only claim to statewide victory this year was in Nebraska, where Ben Sasse handily won the GOP Senate nomination last week. But although Mr. Sasse aligned himself with Sen. Ted Cruz, R-Texas, he received significant support from officials in Washington. Mr. Sasse held several posts in the George W. Bush administration.