Sen. Ted Cruz, R-Texas, warned Friday that Republicans could face a “Watergate-level blowout” in the midterm elections if they don’t make major legislative strides on taxes and health care.

“If tax reform crashes and burns, if [on] Obamacare, nothing happens, we could face a bloodbath,” Cruz said.

The Texas senator made his comments here during a moderated discussion at a gathering of more than 100 wealthy conservative donors who belong to the powerful political network backed by the billionaire industrialist Koch brothers, Charles and David.

The alarm bells Cruz sounded in invoking the political scandal that brought down Richard Nixon’s presidency and set back the GOP in subsequent elections, came amid growing worries among Republican strategists and donors that the party’s lack of legislative achievements is becoming a major political liability heading into 2018.

Cruz was one of a handful of elected officials attending the donor summit. The Washington Post and other news organizations were invited to cover the two-day gathering, on the condition that the donors present not be named without their permission.

President Donald Trump and Republican congressional leaders have embarked on a sweeping revision of the nation’s tax laws. They are aiming to shepherd their plan into law in the next few months, and are hopeful that if they accomplish that, some of the disappointment in the party over the failure to dismantle the Affordable Care Act will evaporate.

In a panel discussion focused on tax reform, Sens. David Perdue, R-Georgia, and Tim Scott, R-South Carolina, warned of dire political consequences if the endeavor is not successful.

“Failure is a starting process, in my opinion, to losing the House, which will manifest in 2018 if we don’t get this done,” Scott said, arguing the stakes are huge. “And frankly, I think it destabilizes the Senate, we lose the Senate as well.”

Disagreements among Republicans threaten to sink the tax push. GOP discord decimated the effort earlier this year to repeal and replace the ACA.

The Koch network is aggressively pressing Republicans to succeed in their tax push and is making it the top policy priority at the moment.

More broadly, the Koch network plans to spend between $300 million to $400 million on policy and political campaigns during the 2018 election cycle.

Vice President Mike Pence is scheduled to address donors here later Friday. Wisconsin Gov. Scott Walker is also slated to speak.

In his remarks, Cruz praised Trump for nominating Neil M. Gorsuch to the Supreme Court earlier this year. He called it the “single best” thing Trump has done.

In a dig at his own caucus’s dearth of achievements, Cruz called Senate’s confirmation of Gorsuch, “damn near the only thing Senate Republicans have done.”