“I think we’ve got a good voice in the process, yes,” Sen. Shelley Moore Capito (R-W. Va.), seen here in a file photo, told reporters Monday evening. “We’re going to be talking about it probably for the next several weeks.” (Tyler Evert AP/AP)

The Senate has broken into a series of “working groups” to begin writing its own version of legislation to replace the Affordable Care Act. There’s the leadership-driven group, a group of moderates and there was talk about a more conservative group before it was mostly absorbed into the leadership group.

But the most powerful bloc in the Senate, based on the size and clout of its members, are the Republicans who come from states that took advantage of the 2010 health law’s federal expansion of Medicaid to provide insurance to millions of lower-income Americans.

These Republicans come from every type of state, from classic political swing states with Democratic governors like Colorado and Pennsylvania to conservative, largely rural states like Arkansas and Arizona.

All told, there are 20 Senate Republicans who hail from states where their governors accepted federal Medicaid funding to provide increased coverage — a list that includes rising-star conservatives, a recent Republican presidential nominee and the Senate majority leader himself, Mitch McConnell (R-Ky.).

(Jenny Starrs/The Washington Post)

These 20 senators represent more than 4 million constituents whose health-care coverage comes from the ACA’s Medicaid expansion, based on estimates from health-care watchdog Families USA, and they are certain to become the driving force in whatever happens in the Senate’s consideration of health-care legislation.

“I think we’ve got a good voice in the process, yes,” Sen. Shelley Moore Capito (R-W. Va.), told reporters Monday evening. “We’re going to be talking about it probably for the next several weeks.”

Her state has more than 180,000 beneficiaries of Medicaid expansion, which is about 10 percent of West Virginia’s entire population.

Issues like this are what separates House members from senators and how they act. All three members of West Virginia’s delegation to the House supported the health-care bill that House Speaker Paul D. Ryan (R-Wis.) edged across the finish line last week with just two votes to spare, even though it included deep cuts to Medicaid that would deny coverage to millions nationwide.

A few years ago Capito was in the House, a loyal vote for party leaders, representing just one third of the state. Had she not been elected to the Senate in 2014 and stayed in the House, it’s possible she would have voted for Ryan and his leadership team’s bill. Now, as a senator representing the entire state, the toll of deep cuts to a program benefiting 10 percent of her constituents weighs more heavily on Capito.

“We need to make sure these folks have access,” she said Monday.

Capito is working with other Republicans to come up with a way for these people to keep their coverage “permanently, either under [Medicaid]or some other kind of way.”

(Peter Stevenson/The Washington Post)

“I mean, we can’t just drop them off and wish them good luck,” she added.

Two months ago, Capito joined Sens. Rob Portman (R-Ohio), Lisa Murkowski (R-Alaska) and Cory Gardner (R-Colo.) in a letter signaling their opposition to the House legislation because it “does not provide stability and certainty for individuals and families in Medicaid expansion programs.”

Those four senators, representing more than 1.3 million constituents benefiting from the expansion, are enough to torpedo anything that does not comport to their wishes on that single issue. With all 48 members of the Democratic caucus opposed to the legislation, McConnell can only afford to lose two Republicans and have Vice President Pence break a tie on whatever bill they craft.

But that quartet speaks for a larger group of Republicans, who have been quietly supporting their efforts.

“I know this, in my state, it’s a Medicaid-expansion state. We have a problem with the bill. We have a problem with what came over from the House,” Sen. John McCain (R-Ariz.), the 2008 Republican presidential nominee, told reporters Monday.

McCain declined to specify how the Medicaid issue should be handled in the Senate, but he made clear that the House bill was a non-starter in Arizona, where roughly 418,000 residents are taking advantage of the decision by the previous governor, a Republican, to accept the federal Medicaid funds.

“I am not looking at the House bill. I am looking at what we need to do here in the Senate,” he said.

Even Sen. Tom Cotton (R-Ark.), a staunch conservative some view as presidential timber one day, has declared his distaste for the House bill. “It was moving too fast. I didn’t think it got it right, that it was better to slow down, and get it right rather than get it fast,” Cotton said at a Little Rock town hall last month, in response to a question about the Medicaid expansion.

More than 300,000 Arkansans, more than 10 percent of the state’s residents, have benefited from the expansion. Cotton has also not taken a formal position on how he wants to repeal the ACA while helping those using Medicaid for coverage, other than to say he wants flexibility for governors.

Gardner is a key player in this negotiation. He’s from the large, influential class of 2014, which delivered the majority to McConnell and includes a half-dozen new senators that represent states that took the extra Medicaid funds.

Gardner also is chairman of the National Republican Senatorial Committee, making him a key ally to McConnell and giving him a deeper understanding of how the issue will play in the 2018 midterm elections.

Two Republicans that Democrats are targeting next year, Sens. Jeff Flake (Ariz.) and Dean Heller (Nev.), come from states that took the Medicaid money, and most of the top Democratic targets that Republicans are eyeing also come from states with the expanded federal funding.

Screw up this issue, and Republicans will have handed Democrats a big weapon next year.

“Look,” Gardner said, “we’re just going to begin the conversation about finding a bill that can pass.”

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