AARP doesn't want any senator to support the Republican healthcare proposal introduced on Thursday.

The organization dedicated to lobbying for older Americans over 50 years old took issue not only with some of the cuts the legislation would make but also the circumstances in which it was devised.

"This new Senate bill was crafted in secrecy behind closed doors without a single hearing or open debate—and it shows," AARP Executive Vice President Nancy LeaMond said in a statement. The Senate bill would hit millions of Americans with higher costs and result in less coverage for them. AARP is adamantly opposed to the Age Tax, which would allow insurance companies to charge older Americans five times more for coverage than everyone else while reducing tax credits that help make insurance more affordable."

The group also complained that the bill would make cuts to Medicare and Medicaid.

"AARP is also deeply concerned that the Senate bill cuts Medicaid funding that would strip health coverage from millions of low-income and vulnerable Americans who depend on the coverage, including 17 million poor seniors and children and adults with disabilities. The proposed Medicaid cuts would leave millions, including our most vulnerable seniors, at risk of losing the care they need and erode seniors' ability to live in their homes and communities," LeaMond said. "The Senate bill also cuts funding for Medicare which weakens the programs ability to pay benefits and leaves the door wide open to benefit cuts and Medicare vouchers. AARP has long opposed proposals that cut benefits or weaken Medicare."

The bill introduced Thursday follows the passage of the healthcare reform bill passed by the House, which aims to partially repeal and replace Obamacare care, the signature healthcare law of former President Barack Obama. AARP says that like it did with all the members of the House, it will hold all 100 senators "accountable" for their votes on this "harmful" bill.

"Our members care deeply about their health care and have told us repeatedly that they want to know where their elected officials stand. We strongly urge the Senate to reject this bill," LeaMond concluded.

50 GOP votes are needed to pass the bill under the process of reconciliation, with a tie-breaker vote from Vice President Mike Pence. Already four of 52 Republicans, Sens. Ted Cruz of Texas, Ron Johnson of Wisconsin, Mike Lee of Utah and Rand Paul of Kentucky, have said they are "not ready" to support the bill in its current form. It is expected that all Democrats will oppose its passage. President Trump chimed in on Twitter on Thursday to say he supports the Senate bill.