(CNN) - With Congress eying to exit Washington in a few weeks, Sen. Chuck Grassley, the chairman of the influential Judiciary committee, dismissed Senate Majority Leader Mitch McConnell's claim that a major criminal justice reform bill doesn't have the support of the majority of Republicans in the Senate.
At an event Tuesday moderated by The Washington Post, the Iowa Republican said that the bill could pass in three or four days, and would lose Republican support if it gets punted to 2019, when Democrats take control of the House.
"If McConnell will bring this up, it will pass overwhelmingly," Grassley said.
Grassley helped write the legislation, known as the First Step Act, which would allow thousands of current and future federal inmates get out earlier, and rehabilitate back into society through halfway houses, home confinement or other supervision, by reducing drug-related mandatory sentences and making more offenders eligible for early release through earning credits awarded by completing certain activities and programs.
McConnell, the Senate Republican leader, has not said publicly whether he supports or opposes the bill. When asked by CNN Tuesday whether he would put the bill on the floor this year, McConnell said "we're still talking."
But McConnell said Monday in a Wall Street Journal interview that the First Step Act is "extremely divisive" among his fellow Republican senators, even though it "does have a lot of support from both" parties. After this week's services celebrating the life of the late President George H.W. Bush, McConnell noted that Congress has only two weeks before it leaves for the Christmas holiday, making it "very hard to figure out how to shoehorn" the bill through Congress.
"I'm pretty confident given the broad support it has that it would pass next year," McConnell added.
With the support of President Donald Trump, the First Step Act is expected to easily pass the Republican-controlled House should McConnell decide to put it up for a vote and send it to the other chamber. McConnell, however, is loathe to pass bills that split his party, and he claimed Monday that "there are more members in my conference who are either against it or undecided than are for it."
Grassley disputed McConnell's math as well, tweeting Tuesday that more than half of the 51 Republican senators support the bill.
"Ldr McConnell said he would need to have 60+ votes to bring criminal justice reform up & wanted to show large amount of Republican support," Grassley tweeted. "We have delivered. More than 1/2 of the Republican caucus supports the First Step Act LET'S VOTE!"
The First Step Act would also retroactively apply the 2010 Fair Sentencing Act, which reduced the disparity between powder and crack cocaine-related offenses, affecting the sentences of around 2,600 prisoners.
At The Washington Post event, Sen. Dick Durbin, D-Illinois, noted that he and former Alabama Sen. Jeff Sessions —a conservative and Trump's former attorney general — struck that bipartisan compromise in 2010. Durbin said he was open to negotiating other provisions in the First Step Act to bring along Senate Republicans wary of the bill.
"The deal will be closed when one senator steps up and says it's time — and that's Sen. Mitch McConnell," Durbin said.
This story has been updated.
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