Republicans’ Obamacare repeal is effectively dead. Again.

Senate Republicans are hurtling toward a last-ditch health-care vote sometime this week, but they almost certainly don't have the votes to repeal and replace the Affordable Care Act. Sens. Rand Paul (R-Ky.) and John McCain (R-Ariz.) are firm “no” votes, with Sen. Ted Cruz (R-Texas) saying Sunday he's opposed to the bill "right now." Sen. Susan Collins (R-Maine) said she's strongly leaning against the bill, and other opposition is piling up.

The bill in question, the Cassidy-Graham plan, would dissolve ACA marketplaces, slash Medicaid funding and give almost all of the federal money propping up Obamacare to states to create health programs as they wish. Those grants would grow slowly and disappear within a decade. It also would allow states to waive many ACA regulations, such as those that prohibit penalizing people with preexisting conditions. In short, it would get rid of Obamacare and much of the federal government's role in health care.

Time is running out, too. The vote needs to occur before Sept. 30, the last day of the 2017 fiscal year. After that, Republicans won’t be able to use budget reconciliation, a special Senate procedure that allows them to pass the bill with only 50 votes rather than the usual 60.

Who might vote no?

We’re tracking every senator’s position on the bill. Assuming no Democrats vote for it, Senate leaders can afford to lose only two Republican votes. The Senate’s previous health-care bill — the “skinny repeal” — fell one vote short of passing with three Republican no votes: Sens. Susan Collins (R-Maine), Lisa Murkowski (R-Alaska) and John McCain (R-Ariz.). Below we take a look at some groups of Republicans who might have a reason to vote no, highlighting those who have said that they are opposed and those who have said that they have concerns. The other senators either support the bill or are undecided or unknown.

Thirty-five states are expected to lose funding by 2026 under Cassidy-Graham according to an analysis by the Kaiser Family Foundation. These states are generally those whose ACA implementation has been most robust and successful: Many expanded Medicaid and aggressively signed people up for the exchanges, meaning they get more money from the federal government. And the more money they’re getting now, the more they may lose under this legislation.

There is opposition to the bill on both sides of the Republican ideological spectrum (more on how we categorized the lawmakers here). Relatively moderate senators are cautious about taking drastic measure to roll back Obamacare. Some of the most conservative senators are concerned that this bill may not go far enough.

In whatever form it takes, the Senate bill is expected to be unpopular. That makes it a riskier yes vote for senators who will be up for reelection in 2018, such as Republican Dean Heller, from the battleground state of Nevada, who is co-sponsoring the new bill.

Here’s a continuously updated list of where Republican senators stand on the current bill. Click on the lawmaker to read why he or she took that position. Did we miss something? Let us know!