Lawmakers were trying to block a constitutional amendment, backed by Republicans in the state senate, that would protect religious people and organizations that oppose same-sex marriage.

AP / Jeff Roberson Democratic State Sen. Jamilah Nasheed is one of the filibuster leaders.

Republicans in Missouri's state senate broke a 39-hour Democratic filibuster Wednesday morning, voting to advance a bill that would protect religious people and organizations opposed to same-sex marriage. The GOP state senate voted 23-9 to end debate Wednesday morning by using a rare procedural move called a "previous question." The senate must pass the bill again on a final reading — which is scheduled for Thursday when the senate convenes at 10 a.m. Central Time — before it goes to the state house. If approved by both chambers, the bill must be approved by popular vote at the ballot.

One of the Democratic leaders of the filibuster posted on Twitter, "we fought the good fight": We fought the good fight today. But this is just one battle in the long war against injustice. Thanks 4 all your support,my friend!

Democrats are in the legislative minority in Missouri's capitol, but they seized control of the microphone on Monday afternoon by taking advantage of state rules allowing legislators to hold up a bill by talking or debating its merits, also called a filibuster.

Both procedure and theater, the action drew national attention and support from major companies, presidential candidates, and the governor. "I want to see us go for 24 hours," said Democratic Sen. Maria Chappelle-Nadal halfway through the marathon session.

Critics say the measure would “enshrine discrimination into the state constitution.”

Democrats traded off the floor in three-hour shifts, with banter that took on the texture of a morning talk show: eyedrops, watercolor painting, health care management, and, of course, the issue at hand. They said the measure to protect those opposed to same-sex marriage would “enshrine discrimination into the state constitution.” At issue is Senate Joint Resolution 39, which would create a constitutional amendment that prohibits the state from penalizing clergy, religious organizations, and individuals who act on their religious beliefs against marriage between two people of the same sex. It is one of dozens of religious freedom bills filed in legislatures around the country. Republican Sen. Bob Onder, the bill’s sponsor, issued a statement on Tuesday responding to the bill's critics. "This measure does NOT discriminate," he said. "We are fighting for fairness and the right for people to freely live out their faith while not infringing on the rights of others," the statement continued. "It’s about liberty.” The Republican state caucus tweeted that the bill was "a shield, not a sword."

17 hours later, Senators are still debating #SJR39. "It's a shield, not a sword." #ShowMeReligiousFreedom

But major corporations and politicians argued otherwise. Hitting close to home, the Missouri-based agricultural giant Monsanto issued a statement Tuesday amid the filibuster when asked about rumors that the company was lobbying to defeat the measure. "At Monsanto we remain committed to diversity and inclusion for all. This legislation would be contrary to that position," Monsanto spokesperson Charla Lord told BuzzFeed News. "Monsanto is calling on other businesses and the agricultural community to join the company in speaking out against discrimination here in our home state of Missouri and around the world." The St. Louis chamber of commerce also weighed in, saying SJR 39 "sends the message to the rest of the country that Missouri condones discrimination." The group called to amend the bill. Likewise, Dow Chemical, which maintains plants in the state, announced during the filibuster that it opposed the legislation.

Dow opposes Missouri Senate Bill #SJR39 and any efforts that allow for discrimination of any colleague or citizen.

Politicians, including Democratic presidential candidates Bernie Sanders and Hillary Clinton, weighed in while the filibuster persevered through the Tuesday primary.

Marriage equality is the law. I stand with those filibustering in MO to make sure discrimination won't be. -H https://t.co/u34dGDcVeY

Gov. Jay Nixon, a Democrat, also rallied for the filibuster. The bill does not require his signature to become law.

Inspired by senators' heroic stand against discrimination in #MO. The nation is watching & cheering you on! #SJR39 #NotInMyState