And the government’s consolidated terrorist watchlist is notoriously unreliable . It has ensnared countless innocent Americans, including disabled war veterans and members of Congress. Nearly half of the people on these watchlists were designated as having “no recognized terrorist group affiliation,” according to documents obtained by The Intercept in 2014.

While sit-in participants are also advocating for expanded background checks and an assault weapons ban, their primary call to action is for a vote on a measure that would ban gun sales to people listed on a federal government watchlist — a move clearly designed more for its political potency than for its effectiveness.

But this unusually bold and moving tactic was undercut by the fact that its chief goal is a political gimmick that would do little to stop gun violence, while expanding the use of a deeply flawed anti-terror watchlist.

Congressional Democrats took the unprecedented step of conducting an actual sit-in on the floor of the House of Representatives on Wednesday, demanding that Republican leaders allow votes on gun control legislation.

Indeed, many of those involved in today’s sit-in have themselves recognized these problems in the past. In a 2014 letter addressed to the Department of Homeland Security, lawmakers including Rep. John Lewis, D-Ga., the civil rights hero leading today’s sit-in, complained that the current process for appealing designation on the federal no-fly lists “provides no effective means of redress for unfair or incorrect designations.”

Some members exaggerated the measure’s potential impact. “If the laws had been in place that the Senate tried to pass in the horrific tragedy of Orlando, there would not be 49 dead. If the laws had been in place — no fly, no buy,” Rep. Sheila Jackson-Lee, D-Texas, said. “Let’s do this for the victims of the Pulse night club in Orlando,” intoned Rep. Suzanne Bonamici, D-Ore.

But even though Orlando shooter Omar Mateen was reportedly once on the terrorist watchlist maintained by the FBI, he was removed from the list before the tragic mass shooting.

House Democrats can force a bill to come up for a vote on the floor if they are able to get 218 signatures from members on what is called a discharge petition. A discharge petition for New York Republican Rep. Peter King’s version of legislation to bar Americans on the terrorist watchlist from purchasing firearms currently has 181 signatures. Ironically, King is notorious for targeting Muslims, having held hearings in 2011 accusing them of not properly cooperating with law enforcement to identify terrorists.

Democrats have no similar discharge petition on other gun legislation, such as Rhode Island Democratic Rep. David Cicilline’s bill to ban assault weapons.

Update: 9:20 p.m. ET

Progressive Change Campaign Committee co-founder Adam Green tweeted that his organization has been lobbying for a discharge petition for an assault weapons ban for a week: “Zero takers. [House Minority Leader Nancy] Pelosi is the problem. …Very frustrating.”

Top photo: Rep. John Lewis, D-Ga., and others sitting in on the floor of the House of Representatives.