Washington — The Senate is beginning what's expected to be a marathon vote series on Wednesday, as Republicans move ahead with a plan to fund immigration agencies under the Department of Homeland Security without help from Democrats.

Senate Republicans released a budget resolution and took an initial vote earlier this week as they kickstarted an effort to fund Immigration and Customs Enforcement and parts of Customs and Border Protection through budget reconciliation. The process allows the GOP to move ahead despite opposition from Democrats, who have demanded reforms to DHS' immigration enforcement. 

With the plan, Senate Republicans are aiming to fund the agencies for more than three years, ensuring they remain funded through the remainder of the Trump administration. 

The budget resolution would authorize the Senate Judiciary and Homeland Security committees to draft legislation to increase spending by up to $70 billion each, which would be used to fund Immigration and Customs Enforcement and parts of Customs and Border Protection. The final bill's price tag is expected to be around $70 billion total, though Republicans say the figures are aimed at giving the committees flexibility. 

Before the resolution can be adopted, the chamber must conduct what's known as a "vote-a-rama," in which senators can offer an unlimited number of amendments and force the chamber to cast vote after vote. Voting on a series of amendments offered up by Democrats began shortly after 9:30 p.m. ET.

Senate Minority Leader Chuck Schumer said at a news conference on Wednesday that Democrats will put up "lots of amendments," promising a variety of votes aimed at putting Republicans on the record, especially on affordability issues. 

"This will be a reconciliation of contrasts, and we are relishing that fight," Schumer said. "Republicans want to shell out billions of dollars to Donald Trump's private army without any common-sense restraints or reforms. Democrats want to put money in people's pockets by lowering their costs."

The New York Democrat said Republicans "are about to learn the hard way that when they refuse to reduce costs, they lose."

"This will be a reconciliation of reckoning for Senate Republicans," he added. 

Democrats have no way to block the GOP funding plan. Republicans have a 53-seat majority in the Senate, and although most legislation requires 60 votes to move forward, the budget reconciliation process allows Senate Republicans to advance a measure with direct budgetary consequences with only a simple majority.

DHS funding became a flashpoint in Congress after two deadly shootings by federal agents in Minneapolis in January. In response, Democrats pledged to object to any funding for DHS without reforms to its immigration enforcement agencies. 

The department shut down on Feb. 14 amid the stalemate. After weeks of back and forth, Senate Democrats and Republicans failed to reach an agreement on reforms, and opted instead last month to fund the bulk of DHS, while leaving out funds for ICE and parts of CBP. 

The House has yet to take up the Senate-passed funding for the bulk of DHS, which they approved through the traditional appropriations process. House Republicans have indicated that they need assurances that ICE and CBP will be funded, and are waiting for the Senate to move forward with budget reconciliation. Meanwhile, DHS remains shut down, although President Trump has directed employees to be paid on a temporary basis. 

Senate Majority Leader John Thune told reporters Wednesday that he's hopeful the House will move forward soon with the funding for DHS, as agency officials warn that funding will dry up next month. 

"I think that message is being delivered and hopefully will be received, and we can get moving forward with making sure those agencies are funded," Thune said.  

The plan hit a speed bump Wednesday night when Sen. John Kennedy, a Louisiana Republican, made a push to make a number of changes to the bill. But he ultimately released his hold and allowed the voting to move forward. 

Kennedy warned on the Senate floor ahead of the vote-a-rama that there won't be a third opportunity for a reconciliation bill. He stressed that a GOP election bill known as the SAVE Act should be included, along with a handful of affordability-related provisions.

"This is the last train leaving the station," he said. "And I'd like to see us come up with one or two issues that will help the American people with the cost of living and other things that I know Republicans can agree to."