WASHINGTON — Senate Republicans are going their own ways after last week’s passage of an Obamacare replacement bill in the House, with one doctor in the caucus vowing to keep his pledge to forge a bill that passes “the Jimmy Kimmel test.”

Sen. Bill Cassidy (R-La.), who is married to a fellow doctor and set up a low-income clinic in Baton Rouge years before running for Congress, told supporters in a Monday email that he’ll be “working tirelessly on a new bill to ensure that the final version of this reform fulfills the contract President Trump made with Americans for lower premiums and protecting those with pre-existing conditions.”

“We have to make sure our legislation can pass the ‘Jimmy Kimmel Test,'” he said in reference to the late-night host’s newborn son’s ordeal. “That is to say a child born with congenital heart disease is guaranteed to get everything he or she needs in the first year of life.”

Cassidy told MSNBC this morning that the House bill contains “assumptions… that are kind of complex to go through,” but “the way to take care of pre-existing conditions is to take the few that are sick and put them in a very large plan where there are many other who are healthier.”

“Again, the Cassidy/Collins [legislation] does that by our feature of allowing states to put you in. Not a mandate. Absolutely it’s like Medicare. I turn 65, I’m on Medicare. Not a mandate. I can call up and say I don’t want it. Otherwise I’m in and my health brings down the premiums for those not so healthy,” he said.

His bill with Sen. Susan Collins (R-Maine), the Patient Freedom Act of 2017, keeps prohibitions on annual and lifetime limits in Obamacare as well as prohibition of pre-existing condition exclusions and discrimination, and allows kids to stay on their parents’ plan until age 26. It also maintains coverage for mental health and substance abuse while allowing states to choose to reimplement the Affordable Care Act, choose a new alternative with 95 percent federal funding and Medicaid expansion matching funds, or choose a new alternative without federal assistance.

“Under our plan everybody of the same age is charged the same amount. And obviously older people cost more. You might get charged a little bit more,” Cassidy admitted. “On the other hand, the credit you would receive if you were eligible for a credit would be commensurate with your age.”

Conservatives, the senator added, “have always said we should equalize the tax treatment between those who get their insurance through their employer and those who don’t.”

“With this tax credit we equalize that treatment, that tax treatment of employer based versus non-employer based. That’s a long-term conservative goal and we accomplish that goal,” he said.

Cassidy called on his Democratic colleagues to “get engaged” in the process of drafting healthcare legislation.

“Whenever I hear a Democrat say ‘I wasn’t called,’ they’re not using the right language. I’m thinking, don’t be passive. Come together. Approach Mitch McConnell with an idea that will lower those premiums for the folks who need it. Don’t be passive, number one,” he advised.

“Number two, if we’re going to fulfill President Trump’s contract to the American voter, I think the only way to get there is through a bill if not Cassidy/Collins, a bill a lot like Cassidy/Collins. I’d like to think we fulfill that contract. I think the president is serious about it. If we fulfill it it’s going to look like Cassidy/Collins.”