Sixteen senators and representatives accepted an invitation to the White House from President Barack Obama on Feb. 24 to discuss ways the administration and Congress could work together to pass a meaningful criminal justice overhaul.

Conspicuously absent was the Senate Judiciary Committee chairman, Iowa Republican Charles E. Grassley, who arguably holds the fate of criminal justice legislation in his hands. Obama did reach out to Grassley a week later to personally invite him to the White House. But Grassley’s initial absence underscores his complicated and unpredictable role in this year’s criminal justice debate.

Grassley has made no bones about his passionate opposition to reducing mandatory minimum prison sentences, as proposed by Republican Sen. Mike Lee of Utah and Senate Minority Whip Richard J. Durbin of Illinois in the so-called Smarter Sentencing Act (S 1410).

On the floor, Grassley has called rolling back such fixed sentences “dangerous,” “ill-conceived” and “indefensible.” Last year, he tried to gut a version of the bipartisan bill, which the Obama administration backs, with an amendment in committee.

Even so, Grassley told CQ Roll Call that he’s ready to start looking for common ground with the bill’s supporters. What’s been missing, he adds, is an invitation — from Obama, from the senators sponsoring the bill, from their staffs — from anyone willing to start a conversation.

“First of all, nobody’s asked me even though for three months, including my speech last week, I said I would be glad to meet people about what we could possibly do because I’m open to some reform,” Grassley says.

Juvenile justice is among his top legislative priorities, and he has said he plans to co-sponsor a bill with Rhode Island Democrat Sheldon Whitehouse to reauthorize the 1974 Juvenile Justice and Delinquency Prevention Act. That law has not been reauthorized since 2002.

Grassley says he thinks there could be some reductions in mandatory minimums, but at the same time he wants to see increases in minimum sentences in other areas, such as child pornography and white-collar crime. He has also cited the need to prevent abuses in the forfeiture of civil assets, and to ensure that offenders receive fair representation.

“It may just be time” to start criminal justice talks, Grassley says. He notes that he “did have the president” on the phone, adding: “I don’t know whether it’s because he realized he made a mistake by not inviting me to the White House when the other people met. The president called me on another issue and at the end of that conversation, he asked me if would I would be willing to come down to the White House.”

Grassley will be “a key partner in this effort,” Anthony Romero, executive director of the American Civil Liberties Union, said at a February event to launch the Coalition for Public Safety, which backs criminal law changes. Romero added: “It’s also true that we will have to be opportunistic.” He said it makes sense to focus first on small changes such as civil asset forfeiture protections.

Backers of the Smarter Sentencing Act aren’t holding out much hope for winning over Grassley.

“The arguments for the Smarter Sentencing Act are merely a weak attempt to defend the indefensible,” Grassley said in a blistering March 10 floor speech. “What I have called the leniency industrial complex refers then to the people who are sentenced to drug mandatory minimum sentences as ‘nonviolent.’ They use that term even though any truly nonviolent offenders would qualify for the safety valve.”

To John Malcolm, a senior legal fellow at the Heritage Foundation, which backs sentencing and other criminal justice revisions, such statements are unequivocal.

“I have serious doubts that someone who refers to any argument in favor of mandatory minimum reform as ‘indefensible’ and anyone who supports such reforms (which would include me) as a member of the ‘leniency industrial complex’ is moveable on this issue,” Malcolm wrote in an email.

Still, advocates of sentencing changes aren’t giving up.

“The chair of the committee taking a position against the bill is unhelpful,” acknowledges Rep. Robert C. Scott, a Virginia Democrat who wrote the House version of the Smarter Sentencing Act with Idaho Republican Raúl R. Labrador. “But he only has one vote. If something gets to the floor and you start having floor votes, he’s back to one.”

This piece originally appeared as the cover story in the April 13 CQ Weekly.