A group of Republicans just launched a desperate Hail Mary to repeal Obamacare

A group of Senate Republicans on Wednesday rolled out a last-ditch effort to repeal and replace the Affordable Care Act, but it is almost certain to face a legislative roadblock.

The bill, written by Sens. Lindsey Graham, Bill Cassidy, Dean Heller, and Ron Johnson, would primarily allocate federal funding for healthcare in block grants to states — a change from the current system, which allocates money based on a percentage of what states spend.

In a statement announcing the release of the bill — named after the senators — Graham touted the idea as a way to give states flexibility on healthcare spending.

"Our bill takes money and power out of Washington and gives it back to patients and states," Graham said. "It takes us off the path to single payer healthcare — which would be a disaster — and puts us on a path toward local control."

The bill has the support of some prominent Republicans, including Sen. John McCain, who cast the pivotal vote that killed the first push by the GOP to repeal the ACA, the law also known as Obamacare. But it does not appear to have the necessary support to pass the Senate.

Sen. Ted Cruz said the bill had the support of about 45 members of the GOP conference. Senate Majority Leader Mitch McConnell reportedly said the bill would get a vote if the senators could persuade 50 Republicans to support it. Typically, leadership tries to find votes for a bill it supports.

The process by which Republicans would have to move the bill, known as budget reconciliation, also presents the biggest challenge, as it stamps a serious time crunch on their effort. The rules that would allow the bill to pass the Senate with a simple majority and avoid a Democratic filibuster are set to expire at the end of the month.

Sen. John Thune, the third-ranking Republican member of the Senate, told reporters that the bill would need a "double-double bank shot" to pass.

The bill does have the support of President Donald Trump, who applauded it in a statement after its release, though he did not explicitly tell other senators to vote for the bill.

"As I have continued to say, inaction is not an option, and I sincerely hope that Senators Graham and Cassidy have found a way to address the Obamacare crisis," Trump's statement said.

Another sticking point is whether key provisions of the proposal would qualify for budget reconciliation under what is known as the Byrd rule, which dictates that any part of a bill that does not affect the budget is stripped out.

Here's a quick rundown of what the proposal would do: