A popular defense of President Trump from his supporters is that his critics will never give him credit — even when he behaves as other presidents have or gets behind ideas that have broad support. We’re seeing some evidence of what they mean after Trump’s endorsement of a criminal justice reform bill.

On Wednesday, Trump officially endorsed the First Step Act, a bill that he said includes “reasonable sentencing reforms while keeping dangerous and violent criminals off our streets.”

The president known more for slamming Democrats than working with them also said: “Today’s announcement shows that true bipartisanship is possible."

Liberal activist Van Jones, who has worked with the Trump White House on criminal justice reform for a while, was the recipient of much chiding on Twitter after he tweeted that Trump “is on his way to becoming the uniter-in-Chief” after his support for the bill.

And on CNN, where Jones is a political commentator, he told host Don Lemon:

“I think you’ve got to give him some credit. . . . I say the 99 times I don’t agree with the president I’m going to give him hell. But on this one, I’ll give him a salute and applause.”

Jones found that many on the left were not willing to “give him some credit,” however.

If the bill is what lawmakers suggest it is, it could be one of the most significant steps in recent history to reform some areas of the criminal justice system.

The House-passed bill focused on reducing prisoner recidivism, but the new Senate package includes language that lowers mandatory minimum sentences for drug felonies, including reducing the “three strikes” penalty from life behind bars to 25 years.

The bill would retroactively apply to the Fair Sentencing Act of 2010, which would reduce the disparity in the sentencing guidelines between crack and cocaine offenses. The bill would also allow judges in some cases to issue sentences for lower-level crimes that are shorter than mandatory minimums.

Part of the backlash to Jones probably stems from Trump’s poor track record with the left on supporting criminal justice reform and his heated rhetoric and prejudgments in the past against people he thinks are offenders. Trump has still not apologized for calling for the death penalty for five black and Latino teenagers known as the Central Park Five, who were falsely accused of physically assaulting a white woman. He has also counseled law enforcement officers to be physically tougher on people they arrest whom they suspect of committing a crime, and he has championed the controversial stop-and-frisk program. And Trump’s recently departed attorney general, Jeff Sessions, was credited with rolling back numerous policies put in place by President Barack Obama’s administration aimed at increasing oversight of problematic police departments.

Rolling Stone writer Jamil Smith was probably speaking for many on the left when he tweeted: “I cannot fully trust any bill that Trump would endorse, criminal justice reform or otherwise.”

Questions about Trump’s true commitment to criminal justice reform have caused many of his critics, especially on the left, to ask more questions before offering praise about the bill. For some, the president’s actions in other areas will always cause them to doubt his willingness to work with those on the left. But to Trump’s supporters, attacks on Jones further their belief that the president will never be able to do anything to win support among those who long ago wrote him off and that he should not pursue the support of these Americans.

It is true that Trump does not have a long track record of attempting to promote bipartisanship. In fact, he is far more known for being divisive. Whether he can change his approach to governing — especially after midterm elections that saw significant gains among those outside Trump’s camp — is yet to be determined. But it is clear that many people are watching him to see how he will lead Americans on both sides of the aisle moving forward.