Senate Democrats are demanding that Republicans abandon their hope of using a criminal justice reform bill to expand mens rea, a legal doctrine that prevents defendants from being charged with crimes they didn't know they were committing, and their opposition may end up shifting the bill even though Republicans control both the House and Senate.

Democrats have charged that Republicans are pushing for the language to make it harder to bring charges against companies, and say they're missing the point of the bill.

"It has nothing to do with sentencing and rehabilitation," Rhode Island Sen. Sheldon Whitehouse, one of the lead Democratic negotiators of the criminal justice reform package, told the Washington Examiner. "It's a voyage into a whole new territory that the bill doesn't cover, which is the underlying substantive federal criminal laws. If they want to go there, we've got lots we'd like to look at."

Those objections are complicating Senate Majority Whip John Cornyn's attempt to recruit support for the bill, which faces significant opposition from Republicans who hesitate to agree to the early release of any federal prisoners. Cornyn and his allies β€” most notably Senate Judiciary Committee chairman Chuck Grassley, R-Iowa, and Tea Party Sen. Mike Lee of Utah β€” revised the bill to alleviate concern that violent offenders would benefit from the reforms, but they're still working to convince most Republicans that they achieved their goal.

They've had some success in that effort, gaining the support of Sen. Thad Cochran, R-Miss., and Illinois Sen. Mark Kirk, one of the most vulnerable Republicans up for reelection.

"We are spending about $60,000 per prisoner every year in Illinois to incarcerate individuals who leave prison more dangerous than when they arrived β€” everyone knows this system is broken," Kirk said on April 12. "My changes to this bill direct savings to fight gangs, which are too often taking children away from their families in Chicagoland."

Behind the scenes, Cornyn's GOP opponents are campaigning against the revised version of the bill. "This isn't surprising coming from one of the most liberal Republicans and only further demonstrates there still isn't enough support in the Senate for a criminal leniency bill," one Senate GOP aide said in response to Kirk's announcement.

Privately, some Republicans grumble that the legislation does more to advance the priorities of the Democratic minority than it does to advance traditional conservative criminal justice reforms, which would reduce the number of federal crimes, especially those committed unwittingly. That's why the Democratic pushback against the GOP's mens rea reform request might make it even more difficult to move the bill.

"[F]or the past twenty-five years, a period over which the growth of the federal criminal law has come under increasing scrutiny, Congress has been creating over 500 new crimes per decade," the Heritage Foundation reported in 2008. "That pace is not steady from year to year, however; the data indicate that Congress creates more criminal offenses in election years."

If Cornyn could add the mens rea language to the bill, he might reasonably count on the support of at least Sen. Orrin Hatch, R-Utah. But Senate Democrats are so far refusing to do so because they worry the provision would make it more difficult to prosecute corporate executives in a variety of cases.

Some Republicans and outside activists hope that House Republicans will pass the criminal intent legislation as part of their reform package, believing that Democrats won't kill the entire criminal justice reform simply because of that policy complaint. But Whitehouse suggested he'd be willing to see the whole bill go down rather than agree to that change.

"I think the mens rea stuff has to come out," he said. "And frankly, if the mens rea scheme was the Koch brothers scheme all along when they got behind this, to load it up with their corporate protection amendments and this was a Trojan horse all along, then shame on them. We weren't negotiated with in good faith, at that point."