AUSTIN, Texas -- Texas took a giant step closer to allowing concealed handguns in college classrooms late Tuesday, with House lawmakers giving their preliminary approval to a so-called "campus carry" measure, barely beating a midnight deadline.

The legislation, one of the two major gun rights bills of the session, had appeared destined to fail, with more than 100 amendments lined up in a Democratic effort to kill it.

But then Democrats abruptly dropped the amendments about 25 minutes before the deadline, and the chamber's large Republican majority forced a vote, approving the measure 101-47.

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"If Republicans wanted to celebrate Christmas in April, they have the votes," said Rep. Trey Martinez Fischer, D-San Antonio, who added that running out the clock was never really an option.

Midnight was the deadline for the House to pass bills that originated in the Senate. A final House vote on the measure Wednesday would set up negotiations with the Senate. A compromise would have to be sent to Republican Gov. Greg Abbott by June 1 to be signed into law.

The vote came at almost the same time the Senate's Republican majority dropped a measure in that chamber that would have protected child welfare agencies that block gays and same-sex couples from adopting children on religious grounds from lawsuits.

Back in the House, Republicans made two major concessions on the guns bill: Private schools, which the GOP has long sought to have exempted from campus carry, would be included, and campuses would be allowed to carve out "gun-free zones." Such zones have yet to be defined and would have to be passed by each school's board of regents.

Some Democrats worried those provisions could be removed before a negotiated bill is sent to Abbott, as similar measures were previously rejected by the Senate.

Campus carry has been bitterly fought over for years in the second-most populous state and got a big boost this year from the Legislature's large, tea party-influenced Republican majority. Abbott has pledged to sign any bill that expands gun rights in his first session.

At least 20 states allow some form of campus carry, but only a handful make it a defined right in state law, as the Texas bill would.

Texas has allowed licensed concealed carry since 1995 and has about 850,000 license holders, a number that has spiked in recent years. License holders must be 21, take a class and pass a background check and shooting test, although lawmakers have watered down licensing requirements in recent years.

Gun rights groups, including the National Rifle Association, say campus carry is critical for student and teacher self-defense in case of a campus shooter or assaults.

"Campuses are not crime-free zones," said Rep. Allen Fletcher, R-Tomball, who sponsored the bill in the House.

The bill has faced fierce opposition from gun control advocates and influential law enforcement and higher education officials, most notably the University of Texas System and Chancellor William McRaven, the former Navy SEAL who spearheaded the commando raid that killed Osama bin Laden.

McRaven has told lawmakers that allowing concealed weapons could make campuses "less safe," intimidate students and teachers and stifle free speech.

In a letter to lawmakers, McRaven said mental health professionals worry the mixture of guns and the emotional and psychological stresses on students, many of whom are away from home for the first time, could lead to more suicides and accidental shootings.

"We don't need guns on our campus to feel safe. We don't need kids carrying guns to feel safe," said Rep. Terry Canales, D-Edinburg, who said he owns a "boatload" of guns. "This still doesn't make any sense."

But McRaven's counterpart, Texas A&M University Chancellor John Sharp, has told lawmakers that having licensed weapons on campus "does not raise safety concerns" for him.