The Supreme Court on Monday declined to hear an appeal from House Minority Leader Kevin McCarthy (R-Calif.) seeking to revive his legal challenge against the proxy voting rules that House Democrats implemented as a safety measure at the beginning of the pandemic.

The move comes after lower courts had rejected McCarthy's suit against House Speaker Nancy Pelosi (D-Calif.), which claimed that allowing members to cast floor votes without being physically present in the chambers is unconstitutional.

The Supreme Court on Monday did not explain the decision not to take up the case, nor did it provide a tally of how many justices voted against hearing it.

McCarthy asked the high court in September to review a decision from the D.C. Circuit Court of Appeals that found that federal courts do not have jurisdiction to hear such disputes between lawmakers over legislative procedure.

"Indeed, we are hard-pressed to conceive of matters more integrally part of the legislative process than the rules governing how Members can cast their votes on legislation and mark their presence for purposes of establishing a legislative quorum," D.C. Circuit Judge Sri Srinivasan wrote in a decision for a unanimous three-judge panel.

“With this failed lawsuit, Republicans have worked to recklessly endanger the health of colleagues, staffers and institutional workers," the speaker said in a statement. "In doing so, they have fought harder to try to score political points than they have fought to help struggling families during the pandemic. They do so with great shame and hypocrisy, as last year alone more than half of the Members of their conference designated a proxy so that they could vote remotely."

A spokesman for McCarthy said, "Members of Congress should show up to work on behalf of their constituents, just as they have since our nation was founded."

"We can't rely on a separate branch of government to make Congress do their jobs as intended by the Constitution, and if Republicans earn back the majority, proxy voting will be eliminated on Day One."

McCarthy and 160 House Republicans sued Pelosi and other House officials in May 2020, arguing that the proxy voting measure was unconstitutional and broke the chamber's long uninterrupted practice of casting votes in person, even during national crises.

"It is simply impossible to read the Constitution and overlook its repeated and emphatic requirement that Members of Congress actually assemble in their respective chambers when they vote, whether on matters as weighty as declaring war or as ordinary as naming a bridge," the group said in their lawsuit.

But as the case made its way through the courts, many House Republicans warmed to the practice and the number of plaintiffs in the lawsuit dwindled. 

When McCarthy asked the Supreme Court to step in, the only other House Republican still pursuing the case was Rep. Chip Roy (Texas).

A spokesman for McCarthy did not immediately respond when asked for comment.

McCarthy has vowed to eliminate proxy voting if Republicans take over the House majority next year.

"I think people should show up to be paid. I think people should work together across the aisle. And if you're here, that's when you can make that happen. And fortunately, in the next year we'll change that," McCarthy said at a press conference in the Capitol last week.

But the Republicans who've ultimately embraced proxy voting include some members of his own leadership team. House Republican Conference Chairwoman Elise Stefanik (N.Y.) and National Republican Congressional Committee Chairman Tom Emmer (Minn.) have both voted by proxy.

Proxy voting was designed for lawmakers to use if they couldn't cast votes in person due to being sick with COVID-19 or needing to quarantine from exposure. Yet lawmakers of both parties have also used proxy voting as a scheduling convenience.

For example, several Republicans used proxy voting last year so they could attend the Conservative Political Action Conference. Others also voted by proxy when they joined former President Trump for an event at the U.S.-Mexico border months later.

Updated 4:25 p.m.