Originally Published: 12 AUG 21 11:15 ET

Updated: 12 AUG 21 12:28 ET

By Dianne Gallagher, CNN

(CNN) -- The Texas state Senate passed Senate Bill 1, an election overhaul bill that would add new restrictions and criminal penalties to the voting process, Thursday morning on a 18-11 party line vote.

The final vote was taken fewer than 20 minutes after a 15-hour filibuster of the bill from state Sen. Carol Alvarado concluded.

Alvarado, wearing a back brace for support, spoke on the bill for 15 hours and four minutes on her feet without sitting, leaning, eating, drinking or using the restroom -- in accordance with Texas rules.

The Houston Democrat concluded her filibuster, surrounded by several of her colleagues who took turns asking questions throughout the night, on the Texas Senate floor just before 9 a.m. CT.

The bill will next head to the House, where Democrats have delayed its passage by vacating the Capitol, though its eventual passage in the Republican-led legislature is virtually assured.

The filibuster itself was mostly symbolic, as there are more than 20 days that remain in the second special session. Alvarado acknowledged on the floor that she would not be able to stop the bill but told the Texas Tribune she wanted to "call attention to what is at stake".

"Senate Bill 1 slowly but surely chips away at our democracy. It adds rather than removes barriers for Texas seniors, persons with disabilities, African Americans, Asian and Latino voters from the political process," said Alvarado during her filibuster. "Senate Bill 1 is a regressive step back in the direction of that dark and painful history."

Republican Texas Sen. Bryan Hughes, the bill's sponsor, has repeatedly said SB1 would make it "easier to vote, harder to cheat."

SB1 includes broad new protection and access for partisan poll watchers, mail-in ballot restrictions, a drive-thru voting ban, restrictions to the early voting timeframe, video surveillance and assistance restrictions.

While the bill does add one extra required hour per day of early voting, it sets a specific timeframe in which voting must be done -- banning extended hours and 24-hour voting, a measure used during the pandemic in Harris County that local officials testified was especially popular with voters of color. SB1 also further restricts local election officials, for example, adding criminal penalties for sending unsolicited ballot request forms. Some Democratic amendments, like a cure process for mail-in ballot mistakes, were accepted in the final version of the bill.

The next stop for SB1 would be in the Texas House, which has been paralyzed for a month due to a lack of quorum. Texas House Democrats continue to intentionally break quorum as a method to block election legislation, like SB1 and the House version HB3, from becoming law. The Texas House speaker signed civil arrest warrants for 52 Democrats this week, after House Republicans voted to direct the Sergeant-at-Arms to send for those members and compel them to return to the House.

Those House members received an email Wednesday morning from the House Sergeant-at-Arms informing them of the civil warrant for their arrest.

"As of this morning, you have not voluntarily appeared in the House chamber and the Speaker has signed a warrant for your civil arrest. As notice to you of this action, I am attaching a copy of that warrant to this e-mail," read the email, in part. "I respectfully request that you appear voluntarily in the House chamber today and report to the Journal Clerk so that your presence can be recorded in the Journal and the House can proceed with its business."

The House Sergeant-at-Arms later walked door-to-door to each of their House offices to find them. None of the absent Democrats were at the Capitol and the warrants were left with staff.

Earlier in the week, the all-Republican Texas Supreme Court temporarily blocked a Democratic state district judge's temporary restraining order that had prevented the arrest of Texas House Democrats, who successfully killed election overhaul bills during the regular session when they walked out in the final hours and in the first special session when they left the state last month.

The members fled to Washington, D.C. then, in part, to avoid arrest since Texas law enforcement does not have jurisdiction outside of the state to execute a civil warrant. They spent weeks trying to put pressure on congressional lawmakers to pass federal voting rights protections.

Although more Democrats have returned to the House floor, the state House has yet to reach quorum in the second special session called by Republican Gov. Greg Abbott. The Republican has vowed to call "special session after special session" until Democrats return and complete the agenda.

The House will attempt to gavel in on Thursday at 4 p.m. CT.

This story has been updated with additional information.