GOP brass riding a wave?

The GOP establishment is poised for a good Tuesday evening as it faces its biggest primary night yet.

With six states set to vote, business-friendly Republicans are expected to defeat conservative challengers in primaries in Kentucky, Georgia, Idaho and Oregon, giving national GOP favorites a slew of victories over social and fiscal hard-liners.

Senate Minority Leader Mitch McConnell (R-Ky.) will likely cruise to victory over businessman and Tea Party candidate Matt Bevin (R). Rep. Mike Simpson (R-Idaho), an ally of Speaker John Boehner (R-Ohio), is the heavy favorite to defeat his Tea Party rival in a race where national groups spent millions.

{mosads}The two candidates who establishment Republicans were most worried about emerging from Georgia’s crowded Senate primary are unlikely to make the runoff. And Dr. Monica Wehby, national Republicans’ favored candidate, is likely to win her Oregon Senate primary.

The wins will likely extend down-ballot as well, in more off-the-radar races. House Transportation Chairman Bill Shuster’s (R-Pa.) Tea Party challenger fizzled from the start, and the establishment favorite is expected to win the GOP primary for retiring Rep. Tim Griffin’s (R-Ark.) seat.

The expected primary results follow a concerted push by establishment Republicans and their business allies to reassert control over the party and defeat the type of hard-line Republicans that have cost them seats in past years.

“It’s a victory for the pragmatic common-sense conservatives who are the majority of the Republican Party, who are more interested in winning a majority than falling on their sword and losing,” said GOP strategist Brian Walsh, a former National Republican Senatorial Committee communications director who still advises the NRSC and is helping the centrist Defending Main Street super-PAC.

“We said we wanted to get involved early and aggressive and talk about the local impacts of these national issues, and we have,” said U.S. Chamber of Commerce Political Director Rob Engstrom, whose group has spent millions to help McConnell, Kingston and Simpson and has also endorsed Wehby and Shuster.

Conservatives are already downplaying Tuesday’s likely results, pointing instead to last week’s primary win by Nebraska Senate candidate Ben Sasse (R) and longtime Sen. Thad Cochran’s (R-Miss.) tough primary challenge in two weeks.

“Sometime we win races. Sometimes we lose races. We always look to support champions of economic freedom, which is why we supported Ben Sasse for the Senate in Nebraska and why we’re also supporting candidates like Dan Sullivan and Tom Cotton,” said Club for Growth spokesman Barney Keller.

But while Republicans will likely get their most electable candidates in most races — as they look to win the six seats they need for Senate control — some of those have taken a toll.

Georgia’s already-nasty primary will continue for another two months, McConnell’s GOP challenge forced him to spend millions and Wehby has had some bad press in recent days.

“Mitch McConnell is still in a tight 50-50 race tomorrow, the primary in Georgia is only going to get uglier and in Oregon a candidate that already faced an incredible uphill battle has now been unbelievably damaged by some of the worst press a candidate has had in this election cycle,” said Democratic Senatorial Campaign Committee spokesman Justin Barasky. “We feel good about all three races.”

Here’s a full rundown of the races to watch on Tuesday.

GEORGIA SENATE

Businessman David Perdue (R) is expected to top the crowded GOP Senate field, leaving Rep. Jack Kingston (R) and former Georgia Secretary of State Karen Handel (R) battling for the other runoff slot.

That scenario is a relief for national Republicans who’ve sweated about the prospect of Reps. Phil Gingrey (R) or Paul Broun (R), two flawed candidates with a history of gaffes, advancing.

The race between Perdue, Kingston and Handel has already gotten nasty, however, and Republicans expect it to get even worse in the runoff. Kingston and Handel have painted Perdue as an out-of-touch millionaire businessman who laid off workers and outsourced jobs. Perdue has pounded Kingston as a creature of Washington, and has accused Handel of leasing a luxury vehicle on Georgia’s dime.

Waiting in the wings is well-funded Democrat Michelle Nunn, the daughter of former Sen. Sam Nunn (D), who has polled competitively with Republicans.

KENTUCKY SENATE

McConnell had a big lead over Bevin from the start, but he’s had to spend millions to keep it instead of save that money for his race again Kentucky Secretary of State Alison Lundergan Grimes (D). And despite his heavy spending, much of it on positive ads, the general-election polls have stayed close.

Republicans feel good about the race, but admit the primary has been a distraction.

“McConnell has had to have national coverage for a year and a spotlight unlike any other,” said one national strategist who added that that has allowed Lundergan Grimes to avoid scrutiny. “That’s not been helpful in the least.”

Kentucky and Georgia are Democrats’ best pickup opportunities this cycle, though both conservative Southern states remain tough climbs.

OREGON SENATE

Democratic-leaning Oregon is a steeper uphill battle for the GOP, though Republicans think Sen. Jeff Merkley (D) could be beatable. They are high on Wehby, a centrist on social issues who has led conservative state Rep. Jason Conger (R) in the few public polls of the race.

But while Wehby is likely to win her primary, she’s had a tough week. Wehby has faced national coverage of her ex-boyfriend’s accusations that she stalked him in a police report, though he has since walked back that claim and is funding a super-PAC backing her. On Monday, a report showed her ex-husband accused her of “ongoing harassment” during their divorce. She claimed he had been violent with her. 

ARKANSAS SENATE

Sen. Mark Pryor (D) and Rep. Tom Cotton (R) will also officially secure their nominations on Tuesday. Both are running unopposed and have been focused on each other for months.

HOUSE RACES

In Idaho, Simpson is expected to defeat Tea Party candidate Bryan Smith (R). Simpson raised and spent huge sums and had more than $2.5 million in help from center-right outside groups. Smith had the backing of the Club for Growth, which spent a half-million dollars, but threw in the towel in late April and stopped running ads as it became clear that Simpson was going to win.

In Oregon, National Republican Congressional Committee Chairman Greg Walden is expected to easily defeat Tea Party challenger Dennis Linthicum, though Walden has taken the race seriously and spent heavily.

Another Democratic House candidate with big-name support doesn’t have as easy a path. Former Rep. Marjorie Margolies (D-Pa.) has the support of former President Clinton and former Secretary of State Hillary Clinton. The Clintons’ daughter, Chelsea, is married to her son.

But while Margolies began the race as the best-known candidate in the heavily Democratic Philadelphia-area district, she’s struggled to raise money and Pennsylvania state Rep. Brendan Boyle (D) has shown some late momentum. Dr. Valerie Arkoosh (D) and state Sen. Daylin Leach (D) are also in the race.

Arkansas Republicans will also decide on their nominees to replace Cotton and Griffin. Businessman Tommy Moll (R) and state Rep. Bruce Westerman (R) are the two candidates vying for Cotton’s seat and will face former Federal Emergency Management Agency Director James Lee Witt (D) in the heavily Republican district this fall. In a more competitive Little Rock district that Griffin has vacated, businessman French Hill (R) appears to have the edge in his race against Tea Party favorite and state Rep. Ann Clemmer (R), though a third candidate in the primary means it might head to a runoff. Republicans feel better about Hill’s chances against former North Little Rock Mayor Patrick Henry Hays (D) than about Emmer’s chances.

Georgia’s Senate race has also created a cluster of open House seats. Races to replace Gingrey, Broun and Kingston in heavily Republican districts are all expected to head to runoffs, as is the GOP primary to face Rep. John Barrow (D-Ga.) in the Republican-leaning seat.