The Senate is likely to hold test votes Thursday on four immigration proposals, none of which has an obvious route to passage or a clear-cut coalition of lawmakers backing it.

Democrats emerging from a meeting late Wednesday were noncommittal about their support for a compromise reached by the so-called Common Sense Coalition, one of the four proposals likely to get a cloture vote when the chamber reconvenes Thursday. Sixty votes are needed to advance.

The deal would give 1.8 million “Dreamers” a path to citizenship in return for $25 billion to build President Donald Trump’s U.S.-Mexico border wall. It would also place some limitations on Dreamers’ ability to sponsor extended family members for visas.

Congress is trying to pass legislation that would prevent nearly 700,000 Dreamers enrolled in the Deferred Action for Childhood Arrivals, or DACA, program from losing protections currently keeping them from being deported. Trump set a March 5 deadline for Congress to act but two courts are blocking the administration from ending the program.

Watch: Senate Leaders Open Immigration Debate With Dispute Over How to Start

Sen. Lindsey Graham, a staunch advocate for Dreamers and member of the bipartisan coalition, said the deal would forgo changes to the diversity visa lottery because discussions over the program had become “too politically toxic.”

“I think it’s the best thing left,” the South Carolina Republican said of the coalition’s proposal.

Moderate Democrats, especially those facing tough re-elections this year, are likely to support the measure. Missouri Sen. Claire McCaskill told reporters she would back it but Democrats would likely not vote en bloc to support it.

“It’s really tough for some of them,” she said. “Everybody’s going to make up their own mind on every one of the amendments.”

Republican support for the bill is also a nagging unknown. Senate Minority Whip Richard J. Durbin said he thinks the proposal currently has the support of eight or nine Republicans. Even if all 49 senators in the Democratic Conference voted for it — which may not happen — 11 Republicans would need to sign on.

The bipartisan group’s proposal arrived as the Senate’s week-long immigration debate finally began in earnest Wednesday. Originally billed as a free-wheeling, open-ended affair, the debate stalled at the starting line Tuesday after Democrats made repeated procedural objections over which amendments lawmakers would take up.

“The Senate was open for nine hours yesterday alone, nine hours we could have spent processing amendments and proceeding to votes,” Senate Majority Leader Mitch McConnell said. “Nine hours down the drain because Democrats won’t let us start the debate they spent months demanding.”

In addition to the bipartisan group’s proposal, the Senate will likely vote to invoke cloture on three other amendments to the shell bill serving as the immigration vehicle.

The first, by Judiciary Chairman Charles E. Grassley of Iowa, represents Trump’s “four-pillar” framework. It is the favorite of McConnell, who has consistently plugged it as the only proposal that has a chance of being signed into law. But Democrats vehemently oppose it and will almost certainly block it from advancing.

The second, called up by Durbin, represents a deal struck recently by Delaware Democrat Chris Coons and Arizona Republican John McCain that Trump has already declared a nonstarter.

The third amendment, called up by McConnell for Pennsylvania GOP Sen. Patrick J. Toomey, is unrelated to the Dreamer debate and would instead seek to withhold funding from “sanctuary” jurisdictions that decline to cooperate with federal immigration laws.

The Toomey proposal is one of several GOP amendments seen by observers as being designed to force incumbent Democrats from battleground states to cast uncomfortable votes that could be used against them in this year’s midterms.