The path to any quick passage of a Senate policing overhaul got rockier Tuesday, with Senate Minority Leader Charles E. Schumer signaling Democrats’ willingness to block the measure unless their GOP colleagues start over with bipartisan negotiations.

“This bill is not salvageable, and we need bipartisan talks to get to a constructive starting point,” Schumer, along with Democratic Sens. Cory Booker of New Jersey and Kamala Harris of California, said in a letter sent to Majority Leader Mitch McConnell on Tuesday.

Democrats have been critical of the GOP plan led by Sen. Tim Scott, R-S.C., and have griped about being cut out of the process. Schumer called out McConnell, saying the Kentucky Republican was looking to make a point and not making a serious effort. 

“Drafting a partisan bill, dropping it on the floor and saying, ‘Take it or leave it’ seems to be much more about getting the burden of dealing tough issues off Republican shoulders, without doing anything,” Schumer said at a news briefing Tuesday afternoon.

McConnell placed the bill on the Senate calendar last week and teed up a procedural vote on Wednesday, requiring at least 60 senators to agree.

Booker, who called the bill “impotent” on the Senate floor, said it does not even serve as a starting point for a baseline of negotiation.

“[McConnell] is setting this up for failure so that he could check a political box and move off of an issue that millions of Americans want us to deal with in a bipartisan way,” Booker said Tuesday afternoon.

[Policing overhaul hinges on compromise]

He warned in a floor speech earlier in the day that if the bill passes in its current form, “we will be back here again the next time another officer uses deadly force.”

Scott, defending his bill Tuesday afternoon, pushed back on Democrats’ complaints for being cut out. “We included Democrats’ priorities by taking a look at the House bill and including them,” he told reporters.

“Wouldn’t it be more successful if the Democrats would come to the table, have a motion to proceed so that we can actually have a conversation about adding their amendments?” he asked.

Scott, talking to reporters after the party caucus lunches, pointed to earlier comments he made suggesting that his bill shares about 70 percent of its proposals in common with the Democrats’ House proposal. Booker called that statistic “fundamentally not true.”

Rhetoric between the two sides escalated in recent days as Democrats prepare to push their own measure through the House. That bill includes what Democrats say is stronger language to force state and local law enforcement departments to make changes.

Sen. Roy Blunt, R-Mo., told reporters that the policing legislation effort is probably dead if Democrats stick to their position. “There’s probably no path forward in this Congress if they block debate tomorrow,” he said.

Blunt said a conference committee on the GOP-led Senate bill with the eventual Democratic House bill would be the place for compromise and changes to satisfy both sides. “But we are so out of the mode of how to make a law that nobody can seem to figure that out anymore,” he said.

But McConnell told reporters that if Democrats vote against proceeding to the bill and block it, that won’t be the end of the line. He said he’ll move to reconsider the bill, which would allow him to bring it up again later.

Sen. Charles E. Grassley, R-Iowa, praised the GOP bill on the floor. He said Republicans are “ready to work with Democrats on police reform” and expressed hope that Democrats “finally are willing to come to the table.”

Grassley said a successful vote to proceed on the GOP policing bill “speaks volumes.” He then warned, “a vote against proceeding shows the American people that politics are more important than people.”

McConnell also told reporters that if Democrats want to move on, they should vote to lock the Senate floor onto the bill.

“That’s what you do once you get on a bill, is you start horse-trading,” McConnell said. “Each side will say I need so many amendments, you try to reach an agreement. And you let the outcome be determined by the vote.”

[Key differences exist among House, Senate and White House policing plans]

Sen. John Cornyn, R-Texas, called the Democrats’ actions “mindless obstruction” and said he was “not really all that interested in negotiating with hostage-takers.” Later, in a floor speech, the former majority whip encouraged Democrats to commit to working with the GOP to find common ground and work in conference with the House to find suitable solutions.

Scott, along with fellow Republicans Lindsey Graham of South Carolina and Marco Rubio of Florida, met Tuesday with Harris, Booker and Minority Whip Richard J. Durbin, D-Ill., in the Senate Judiciary Committee’s hearing room.

The Republicans wouldn’t say if the group was negotiating the police legislation or if they think a bipartisan deal is possible before the vote on the GOP legislation scheduled for Wednesday.

Asked what the next step would be if it fails, Scott later in the day said, “That’s a question I can’t really answer at this point.”

Katherine Tully-McManus, Jessica Wehrman and Lindsey McPherson contributed to this report.