COLORADO SPRINGS, Colorado — Sen. Ben Sasse (R-NE), whose vote Republican leaders absolutely need if they hope to pass a health care bill in the Senate this week, told a gathering of conservative donors on Sunday that the bill does not really repeal Obamacare — but instead mostly concerns a government program that provides health coverage to the poor.

“This is largely a Medicaid reform package,” Sasse said, during the lunchtime program at the meeting of the Seminar Network, which brings together hundreds of large donors to the organizations under the umbrella of Charles and David Koch.

The comments are a blunt — but defensible — description of the Senate bill, which maintains some of the structure of President Obama’s signature Affordable Care Act as it relates to the individual insurance market, and many of its regulations governing health care in general.

“Republicans have 52 votes in the Senate, we don’t have 60, and to do major legislation requires 60 votes,” Sasse said. “So this is not a full repeal or full replace piece of legislation, and that’s dictated by a whole bunch of circumstances. So we are having a conversation about something that’s much smaller than that.”

The bill also rolls back tax increases that helped fund Obamacare, in a move that would largely benefit high-income earners and some businesses. But as Sasse pinpointed, it is perhaps most notable for its changes to Medicaid.

As my colleague Sarah Kliff wrote last week, summarizing the bill:

The Senate bill begins to phase out the Medicaid expansion in 2021 — and cuts the rest of the program’s budget too. The Senate bill would end the Affordable Care Act’s expansion of Medicaid to millions of low-income Americans. This program has provided coverage to more Americans than the private marketplaces It would also cut the rest of the public insurance program. Better Care would also limit government spending on the rest of the Medicaid program, giving states a set amount to spend per person rather than the insurance program’s currently open-ended funding commitment.

Several Republican lawmakers are attending the Koch retreat at the five-star Broadmoor resort in Colorado Springs. They include at least two senators who have expressed serious concerns over the health bill, Ted Cruz of Texas and Mike Lee of Utah.

Sasse noted their presence but declined to take a position on the bill, saying he has only read about 40 percent of it. “This session is actually on the record, right?” he said, when asked by a moderator how he would vote. “There’s press here? I have nothing to announce today.”