Donald Trump’s nomination made the Republican Party establishment look as if it had lost all influence.

Tell that to Jim Rubens.

The onetime state legislator this week was the latest little-known, underfunded challenger to lose a primary against a Republican senator. He fell to New Hampshire incumbent Kelly Ayotte in a race that received limited attention even as the results were tallied Tuesday. It was emblematic of how this year’s primaries have gone for Republican incumbents.

Ayotte is the latest GOP senator to win a primary this year, a six-month stretch of uninterrupted victories that began in March, when Alabama Sen. Richard C. Shelby won, and ended this week with Ayotte. It’s the second consecutive cycle that the party’s incumbent senators, backed by the establishment, have all won their primaries.

The dominance of the party establishment might seem strange in the year of Trump. But at least in congressional races, that’s exactly what has happened thanks to a concerted effort from party committees, business groups, and leadership-connected super PACs.

It’s a far cry from the election cycles of 2010 and 2012, when tea party-backed insurgent candidates regularly toppled sitting Republicans and won open-seat races.

“At the congressional level, it’s been a fairly status-quo election,” said Rob Engstrom, the national political director for the U.S. Chamber of Commerce. “Despite all the wild predictions about establishment candidates being caught up just because of the top of the ticket, exactly the opposite occurred.”

Maintaining

Party leaders attribute their success to aggressive intervention, including big-money TV ads and opposition research aimed squarely at candidates they deemed unsuitable for the general election. Those efforts were evident in Alabama, where Shelby cruised past a challenger thanks to a targeted, well-funded effort from his campaign and allies.

They had been concerned that the anger so evident in the presidential race — Trump easily won Alabama’s primary — would spill into races affecting Senate and House incumbents.

“In a traditional presidential race with the Republican nomination, there’s historically 20 percent of the electorate that’s carrying pitchforks,” said Scott Reed, senior political strategist at the chamber. “They’re angry, they’re mad, they want to storm the hill.

“This time, it was 65 percent,” he continued. “We were worried last fall what was coming over the hill.”

That nothing did, party strategists say, is a testament to the efforts to insulate those incumbents.

“If left untouched, it would have been the same thing as Trump,” said Josh Holmes, former chief of staff to Sen. Mitch McConnell. “But given the lessons that were learned in 2014, you saw us very aggressively go out and win these elections regardless of what they’re doing at the top of the ticket.”

GOP operatives also say the party’s lawmakers have simply become more conservative, leaving fewer issues for challengers to exploit.

“Incumbents have become more skilled and more focused when it comes to fighting that opposition,” said Steven Law, president and CEO of the Senate Leadership Fund, a super PAC connected to McConnell. “One of the ways the party has responded to these insurgent threats is to make sure it’s more ideologically coherent.”

Future fights

The success in congressional races has party leaders openly discussing whether the same model should be used in the party’s next presidential primary, whether that’s in 2020 or 2024. Many party leaders lament the fact that Trump was able to gain momentum in the race, especially early on, while his opponents attacked one another instead of the eventual nominee.

An intervention that, for example, let GOP voters know about the candidates’ records could have changed the course of the primary, some party strategists theorize. It’s the kind of effort they’re turning over in their heads now, even before the conclusion of the presidential race this year.

“Competitive Senate primaries are a microcosm of national primaries,” Holmes said. “And we know from experience what has worked in the Senate, and I think it behooves the party to have a conversation about how that applies at a national level.”

Rather than party leadership, the effort to intervene in a presidential primary could come from outside groups.

They’ve been effective in congressional races, at least. The Senate Leadership Fund, which is also a sister super PAC to the presidential-focused American Crossroads, ran ads this year on behalf of Rep. Todd Young in the Indiana GOP Senate primary, as he battled fellow Rep. Marlin Stutzman. Young won the race and is running against Democratic nominee Evan Bayh in a key general election battleground contest.

Law, the super PAC’s leader, wouldn’t speculate whether his group would run ads in a GOP presidential primary. But it could publish research on every candidate, he speculated, and let the voters know where all the candidates stand on issues.  

“There’s going to be a re-evaluation of the primary process from 2016,” Law said. “It allowed for very serious problems. And the question is, will it be restricted, or can outside groups play to make sure we don’t end up with the same chaos?”

Party operatives concede that continuing their success will be difficult, especially because the party faces a plethora of open-seat Senate races in 2018, a year when many Democratic senators face re-election. Without the advantages of incumbency, keeping a perfect record in primaries could be a challenge.

In 2018, Democrats will defend seats in potential battleground states like Pennsylvania, Montana, North Dakota, West Virginia, Missouri, Florida, and Indiana.

The club

The GOP establishment’s success this year was in part attributable to the action of the free-market, anti-tax group Club for Growth, which opted against supporting challengers to any Republican senators.

The club always prides itself on its candidate vetting process, careful not to endorse candidates it believes can’t win the primary or general election. This election cycle, however, the group’s leaders were also cognizant of the party’s efforts to hold the Senate, and wanted to make sure it did not add unnecessary obstacles to retaining a majority.

Club President David McIntosh said the group interviewed potential challengers to Ayotte, a lawmaker who did not perform well on the group’s voting scorecard. But it didn’t find a suitable challenger, in part because the threat of losing the seat altogether loomed large.

We didn’t want to “spend resources upsetting the apple cart in a race that is going to be dicey in November,” McIntosh said.

Whether the club continues that approach beyond this year will be determined by how lawmakers act in the next congressional session, he added.

“A big test will come next year,” he said. “Frankly whoever is president, Trump or Clinton, will the Republicans … be aggressive in pushing free-market polices?”