WASHINGTON – Republicans have a lot riding on tax reform — including campaign contributions.

The failure by the GOP-led government to score a significant legislative victory in the year since President Trump was elected has caused some Republican donors to close their wallets.

“I’ve just reached my breaking point with it,” said Dan Eberhart, CEO of Canary LLC, an oilfield services company. “Do something for goodness sakes.”

In protest, he’s stopped sending donations to the National Republican Senate Committee – the main fundraising campaign for Senate Republicans. Instead he’s been meeting with Steve Bannon, Trump’s former chief strategist, who is courting GOP primary challengers to blow up the establishment of Senate Majority Leader Mitch McConnell.

But even Eberhart acknowledges there’s one situation where he could abandon Bannon’s scorched earth approach: passage of tax reform.

”If meaningful tax reform passes, I would do a rethink of my position,” Eberhart said in an interview.

Donations have slowed to the NRSC just as 2018 senate elections are heating up. In August, September and October, monthly contributions have averaged $2.1 million. That’s about half of the $4.7 million average between February and July – prior to the collapse of Obamacare replacement legislation.

Bannon declined to comment, as did the NRSC.

Understanding the high stakes, Trump and congressional leadership have forged a unified front and have pledged to usher through tax cuts by Christmas.

“If there’s anything that unifies Republicans, it’s tax reform,” McConnell said last month after Trump lunched with GOP senators.

Steven Law, president of the Senate Leadership Fund that is working against Bannon, agrees if tax reform fails it will have disastrous consequences.

“Tax reform is a must-do for Republicans… if Republicans are able to get that done I think it fundamentally changes the atmosphere,” Law said, noting donations to his pro-McConnell super PAC are strong.

“(Donors) would be mortified if we didn’t live up to what we’ve committed to on tax reform.”

While the party has been dogged by in-fighting, a victory on tax reform may be the surest way to curb Bannon’s war on the establishment.

“At the end of the day, part of my goal is to not be thinking a whole lot about Steve Bannon much after the end of this year,” Law said. “We want to focus on beating Democrats.”