Supporters of same-sex marriage rally in Sioux Falls, S.D., in 2014. (Jay Pickthorn/Argus Leader via AP)

Democrats in the Missouri legislature are aiming for a 24-hour filibuster of a religious-liberties bill that critics say could lead to discrimination against gay and transgender people.

The bill would put on the November ballot a measure that would amend the state constitution to prohibit the state from penalizing clergy members, religious organizations and certain individuals who on religious grounds choose not to participate in or condone same-sex marriage.

But gay rights groups say it could lead adoption agencies to refuse to place children in same-sex-led households or permit taxpayer-funded homeless shelters to turn away gay couples, among other effects. Moreover, they say, it would enshrine discrimination in the state constitution. They have compared it to a similar bill in Indiana last year that drew huge protests and forced the governor and legislature to backtrack and adjust the bill’s language.

The bill had been up for consideration in the Senate on Monday when, around 4 p.m. local time, Democrats began their filibuster. Seven of the chamber’s eight Democrats (one was out for surgery) spoke in turns throughout the night, some of them catnapping while others stayed up. As the filibuster wore on late Tuesday morning, two weary senators — Jason Holsman and Maria Chappelle-Nadal — kept it up with chatter that sounded at times like a public-radio pledge drive.

The two bantered about everything from local authors to the Democratic presidential primary to generational differences that have led younger Americans to be more open-minded about gay and transgender people.

“Though our numbers aren’t great, they are mighty,” Holsman said at one point. “I feel in good spirits and willing to continue on with our discussion.”

Even if the senators keep it up for the full 24 hours, that does not mean the bill is quashed. Republicans could table the bill and bring it back for consideration another time. However, Holsman and Chappelle-Nadal said they could not recall a filibuster in the state lasting this long.

Missouri is not the only state where debate is heating up over bills aimed at shoring up religious freedom in the face of expanded gay rights. Georgia legislators are battling over a similar measure that has drawn the ire of local businesses, and West Virginia’s legislature overwhelmingly rejected such a bill last week.