Primary season for this year's midterm election is now nearly closed, and the results have produced an outcome not seen in years: Incumbent Republican senators have brushed back all their conservative challengers in a series of victories for the party's embattled establishment.
The results, capped by wins this week by Republican Sens. Lamar Alexander in Tennessee and Pat Roberts in Kansas, seem to run counter to Americans' sour mood about Congress. They should bode well for Republican efforts to gain the six seats needed to win control of the Senate in November.
How much it will help, though, remains debated.
Democrats argue that Republican candidates have won in large part by moving so far to the right that little distinguishes them from the tea party insurgents. That could leave Republicans in competitive races vulnerable in November, they argue.
Establishment conservative figures insist that they are taking nothing for granted.
"We're pleased with the results, but nobody here's dancing in the end zone," said Rob Engstrom, the national political director at the U.S. Chamber of Commerce, which was deeply involved in key Republican primary races. "I still think getting to six is going to be a challenge."
Republicans seem all but certain to pick up three seats currently held by Democrats in West Virginia, South Dakota and Montana. Democratic incumbent Sen. John Walsh dropped out of the Montana race this week in the wake of news that he had plagiarized much of a paper he wrote in 2007 to earn a master's degree at the Army War College.
The GOP has good chances in at least five other states: Alaska, Arkansas, Iowa, Louisiana and North Carolina. Party officials also claim to be competitive in several other states, including Colorado, Michigan and New Hampshire.
Republicans have learned their lessons over the last two midterm election cycles, when outlier candidates such as Sharron Angle in Nevada and Christine O'Donnell in Delaware were blamed for dashing the party's chances for gaining control of the Senate.
The Chamber of Commerce and other business-oriented groups engaged in the primaries early to help favored candidates beat the upstarts. Their interventions also helped put this year's election on track to be the most costly midterm ever.
In all, 10 Republican Senate primaries broke for the establishment's choice, including races in Kentucky, where Sen. Mitch McConnell, the minority leader, swatted back a challenge, and South Carolina, where Sen. Lindsey Graham, once considered endangered for his work on immigration reform, sailed to his party's nomination.
The GOP's populist right and tea party forces, though, have found a measure of victory even in defeat, as their influence has shaped candidates and their campaigns.
Barney Keller, spokesman for the Club for Growth, which has backed insurgents against several incumbent Republicans in recent years — including Chris McDaniel's failed campaign against Sen. Thad Cochran in Mississippi this spring — noted that the group had not gotten involved in the Kansas race.
Nonetheless, incumbent Roberts has shifted his positions and now has a much improved rating from the group.
"There's a ripple effect to everything we do," Keller said.
Democrats insist that those sorts of shifts will help them portray GOP candidates in competitive states as being out of step — particularly on pocketbook issues, such as raising the minimum wage, which conservative groups such as Keller's oppose.
"The establishment got the candidates they wanted, but they're still not good candidates," said Justin Barasky, a spokesman for the Democratic Senatorial Campaign Committee. Moving to the right is "a great strategy for winning Republican primaries, and a terrible strategy for winning in November," he said.
Republican strategists, though, are emerging from primary season optimistic over how races have developed.
"This isn't about tea party voters, who are good people simply trying to get our country back on track," said Brad Dayspring at the National Republican Senatorial Committee.
The establishment's victory, he said, came over "cannibal conservative groups that spent over $20 million against Republican candidates and have not a single thing to show for it."
The Republican Senate campaign has taken a "workmanlike approach — methodical and thoughtful — to each of these campaigns," Dayspring said. "It is entirely possible that we win 10 or more Senate seats" this fall.Copyright © 2015, Los Angeles Times