At the height of the COVID-19 pandemic last year, House Democrats took the unprecedented step to establish rules allowing any lawmaker to vote by proxy if he or she could not attend proceedings in-person because of the pandemic.
A total of 103 U.S. Representatives had active proxy letters filed with the House Clerk as of publication.
"We do want members to take seriously their responsibilities to participate in a legislative process, to cast votes on the floor of the House," said Molly E. Reynolds, a Brookings Institution senior fellow and expert on how Congress functions. "Figuring out how to prevent abuse of the practice while also making it available for people who need it is a real challenge."
Each time a proxy is used, a member of Congress must attest in writing to the House Clerk that they are "unable to physically attend proceedings" for health or safety reasons related to COVID-19. Enforcement is by the honor system.
"They don't want to come in unless they are vaccinated and unless others are vaccinated," House Speaker Nancy Pelosi explained in March.
At least 343 representatives -- Democrats and Republicans -- have filed a notice to vote remotely at least once this year, according to data compiled by Reynolds. The U.S. Senate did not enact a proxy system during the pandemic.
"Graph the number of proxies, and look at how they increase exponentially on Fridays," said Rep. Mike Gallagher, R-Wisc., one of the most outspoken critics of proxy voting. "It's incentivizing the worst behavior among members, which is to say prioritizing fundraising and deprioritizing legislating."
Nearly all House Republicans opposed proxy voting when it began last year, but some have since taken advantage of the flexibility. In one of the most prominent examples, 13 Republicans voted remotely in February while attending the Conservative Political Action Committee (CPAC) conference in Orlando.
Rep. Madison Cawthorn, R-N.C., who was among the CPAC attendees, voted by proxy more than a dozen times this year, despite strong public opposition to the policy and criticizing Democrats who used it as "cowards" for not showing up.
Cawthorn declined comment to ABC News when approached on Capitol Hill. His office also did not respond to an email from ABC.
"I think it's a bad thing; personally, I don't think we need to be doing it at this point," said Rep. Tom Cole, R-Okla., who has criticized proxy voting but also used it. "It's in the rules. You can use it."
Rule or not, Republican Party leaders have argued in court that proxy voting is outright unconstitutional. House Minority Leader Kevin McCarthy has even appealed to the U.S. Supreme Court to strike it down.
"I think people should be here to work to have to be paid when you don't. When you proxy vote, you're not here to debate the bill. You're not in committee [hearings]. It's wrong," McCarthy told ABC News in an interview.
McCarthy would not comment on why so many fellow Republicans have disregarded his admonishment and voted by proxy.
Democrats have voted by proxy more often than Republicans, according to data tabulated by Reynolds at the Brookings Institution. Sometimes for reasons clearly related to COVID-19, but sometimes for reasons that are less clear, she told ABC News.
Democratic Congressman Ron Kind, of Wisconsin, for example, voted remotely on seven bills in June while President Joe Biden was visiting his state. When approached by ABC News, he said that some of his recent proxy votes came after a positive COVID diagnosis for a member of his staff.
"It's a good thing when you have legitimate reasons to be away," said Rep. Seth Moulton, D-Mass. "I have two young girls… I used [proxy voting] when my daughter was born, for example, and I've used it when my daughter was sick just the week before last."
Members of both parties have used remote voting while caring for a sick or dying parent, or when flight delays have kept them stranded far from Washington. Each time, however, they officially attested to the Clerk that the "ongoing public health emergency" kept them from being unable to attend.
"My wife had our first child 16 months ago, I missed votes. But that's how it was," Gallagher said. "You missed votes for legitimate reasons, but proxy voting gets us closer to a nonessential Congress, or a Congress that's just, you know, zooming in to work every day."
Rep. Don Beyer, D-Va., who regularly casts votes for absent Democratic colleagues, told ABC News it's about time everyone gets back to debating and voting in person in Congress.
"The original purpose was just for people who either, where it just wasn't safe to fly or they had some preexisting condition, including being too old," Beyer said. "Now, when people start going to conferences or something, that's a little different."
Florida Democrats Charlie Crist and Darren Soto voted by proxy last year the same day as attending a planned SpaceX rocket launch in their home state, but told the House Clerk they couldn't vote in person because of the pandemic.
Several Republicans and Democrats have used the proxy system while attending political events outside Washington.
"That's something voters should be worried about," Reynolds said, "but I don't think they should automatically assume that just because their member has been voting by proxy, their member hasn't been working."
On Nov. 12, Pelosi announced an extension of proxy voting through the end of the year.
"While some have misused proxy-voting for non-pandemic reasons, it remains a vital protection for the health of Members who may be immunocompromised or be particularly at risk for life threatening complications from COVID," a House leadership aide told ABC News in a statement.
"All across the country, people are getting back to work or schools are opening up again. Congress ought to be working again," said Rep. Steve Scalise, R-La. Asked why so many of his GOP peers are still voting remotely, he replied: "Obviously every member has got to make their own choices while it's there as an option."
The option to participate in Congress remotely remains controversial and unprecedented. And as growing numbers of Americans return to in-person work, many may expect their elected representatives to do the same.
"Figuring out how to protect the process for people who genuinely need it, and while also preventing abuse is going to be a real challenge for an extremely polarized and partisan House of Representatives going forward," Reynolds said.