WASHINGTON, D.C. — Republican Sen. John Cornyn has thundered many times for a "simple up-or-down vote" on the president's judicial nominees, railing against Democrats' stalling tactics.

But it turns out he's not above invoking one of the Senate's obscure tools to block such votes — in this case, on a proposal that would shut down the Texas-based horsemeat industry.

Activists and lobbyists on both sides of the issue point to the junior senator from Texas as one of about a dozen lawmakers suspected of putting an anonymous "hold" on the legislation.

He did not deny it.

"You know, it's a technical matter," Mr. Cornyn said, noting that the bill was caught in legislative limbo for a week anyway, after House leaders discovered that a clerk inadvertently sent the wrong version to the upper chamber.

So everything the Senate or any individual senator had done to that point had been wiped clean.

Advocates for the slaughterhouses said they appreciate the efforts of Mr. Cornyn and others to make sure the Senate holds proper deliberations and doesn't rush a vote just because time is running short.

"Is it proper procedure for the Senate to eliminate an entire industry without a debate on the Senate floor?" said Charlie Stenholm, a former Democratic congressman from West Texas who represents the slaughterhouses. "If there's anybody trying to short-circuit the process, it's the proponents of the bill" who were hoping for a Senate vote without hearings or debate.

This month, the House voted, 263-146, to shut down the horsemeat industry, though two-thirds of the Texans opposed the ban.

Last year, when Congress cut off funding for USDA meat inspectors at the three U.S. horsemeat plants — in Kaufman, Fort Worth and DeKalb, Ill. — Mr. Cornyn was one of 28 senators voting no. Sen. Kay Bailey Hutchison, R-Texas, backed the move.

More than 90,000 horses were slaughtered last year in the U.S. The meat is exported. After years of effort, animal advocates have never come closer to a ban. But time is running out.

The Senate plans just one more week of work before recessing until after the Nov. 7 elections, and it's unclear how much lawmakers will attempt in a lame-duck session.

So a hold could be fatal.

Because holds are filed anonymously, any of the 28 known opponents is a suspect, said Michael Markarian, executive vice president of the Humane Society of the United States.

"Cornyn voted last year to slaughter American horses for the French and Belgians. He's already made his position known," Mr. Markarian said.

Still, he called the Texans' opposition ironic and especially dismaying given that as Texas attorney general, Mr. Cornyn issued an opinion asserting that state law prohibited horse slaughter.

Federal courts have kept the industry alive, ruling that only Congress has the power to shut it down.

"I'll be happy to vote on it again, but my position is pretty clear," Mr. Cornyn said last week.

"If you've got a horse that's worth 200 bucks and the federal government passes legislation that makes it worth zero, and actually ends up costing you money, to me that's a 'taking.' "

The Fifth Amendment bars the government from taking private property "without just compensation."

An owner unable to sell a horse for slaughter could spend hundreds of dollars for euthanasia and burial or rendering.

The legislation was delayed last week because the House clerk inadvertently sent the Senate a version that included "poison pill" provisions tacked on by the House Agriculture Committee.

They would have grandfathered existing horsemeat plants, and made the USDA financially responsible for every unwanted horse in America.

The House never OK'd the changes.

When they realized the error, House leaders were forced to issue a formal "never mind" to the Senate, which sent the bill back Tuesday. The correct version was delivered the next day and is pending in the Senate.

Horse lover Pamela Bertsch was angry when she learned of Mr. Cornyn's stance.

"I don't see how Cornyn can sit there and say 'private property rights,' because then that will also apply to our dogs and cats someday," she said. "[The] U.S. must set boundaries for our companion animals."

But for all the animal lovers who can't bear the thought of horsemeat ending up in Parisian kitchens, lawmakers also have heard from cattlemen worried about a new financial burden.

"It's obviously an emotional issue," Mr. Cornyn said.