Now that President Donald Trump has commuted the prison sentence of former Illinois Gov. Rod Blagojevich — who shook down a children's hospital and tried to sell a U.S. Senate seat — what should Trump do with his big promise? That promise about "draining the swamp"?

Trump should take his promise, dig a hole, and bury it.

This is the worst time for Trump to show mercy to a corrupt Illinois politician, even a tiny swamp weasel like Blagojevich. The news will make Blagojevich seem important, but in political terms, he was nothing, just an empty suit put in the job by Chicago Democratic machine ward boss Richard Mell, his father-in-law.

The other Democratic bosses went along, and so did their unions, and the Chicago tough guys. But then Blago and Mell fell out over a landfill deal. Mell broke bad. The feds moved in.

Blago was a jester who recited Rudyard Kipling's "If" on his way to federal court, a man who sent his wife on reality TV to eat jungle bugs to win him mercy, a man who himself groveled on Trump's show, "The Celebrity Apprentice."

Right now, a federal political corruption investigation rolls through Illinois. These aren't empty suits like Blagojevich. These are the Democratic Party alpha males. And now Blagojevich will emerge from prison triumphant, to praise Trump's name. It will be a circus.

Presidential mercy is all about politics. Bill Clinton released Puerto Rican terrorists just as his wife Hillary was carpetbagging her New York Senate run, needing Puerto Rican voter support.

Barack Obama commuted the sentence of traitor Chelsea Manning, who leaked massive amounts of intelligence that put the lives of Americans overseas at risk. He also released the violent and unrepentant terrorist Oscar Lopez Rivera, a darling of the left.

What does Trump win? He won't win Illinois. But this gives him cover to show presidential love to his buddy Roger Stone. Stone must have been popping Champagne as reporters lined up outside Blagojevich's bungalow in Chicago on Tuesday, waiting for the former governor's glorious return.

Stone was convicted of lying to Congress and interfering with an FBI investigation into Russian interference in the elections. Now, can a pardon for Roger Stone be far behind?

"Oh, give Blagojevich a break," said Karen the Waitress as I wrote this column in the diner. "I feel sorry for his kids, his family. He did his time. What about the other politicians?"

Fourteen years is longer than other crooked politicians get. But it was fair.

Four Illinois governors have been convicted of corruption in my lifetime. Former Republican Gov. George Ryan served only a little more than five years. Ryan's corruption — involving the selling of truck drivers' licenses — led to the deaths of six Illinois children in a horrific, fiery crash. Ryan should have received more time.

Former U.S. Rep. Jesse Jackson Jr., who may have been the beneficiary of the Obama Senate seat deal had not the Blagojevich investigation been abruptly stopped, did time for an unrelated case. Blagojevich never got a dime from his schemes, but Triple J pocketed $750,000 in campaign cash and blew it on junk. He served a little over a year in federal prison and still collects his juicy federal pension.

"(Blagojevich) served eight years in jail," said President Trump on Tuesday. "That's a long time and I watched his wife on television. ... Many people disagree with the sentence. He's a Democrat, not a Republican."

When it comes to corruption, is there a difference, Mr. President?

Trump should bury his "drain the swamp" promise in that wet sump around corrupt bipartisan Washington politics. The earth there has the same sodden consistency as does corruptly bipartisan Illinois.

Dig a hole and sump water rises — in Illinois, in Washington — bringing with it the unmistakable smell of corruption. The politicians become used to it. They thrive in it and play in it, the way some of us got used to the smell of Chicago's Union Stock Yards in the old neighborhood. But blood from a slaughterhouse is foul but honest. It means work and paychecks. This is different. It smells of dangerous infection.

Corruption doesn't much bother the political class. They've become immune. But it does infect the people. And that is the sin of it. Because the people see the connected walking away, Democrats, Republicans, winning pardons, commutations, some fat with federal pensions.

And people wonder: Where's mine? Where's my deal?

Trump sends Blagojevich home as a conquering hero. Look upon Illinois, Mr. President, and behold your great work.

John Kass, based in Chicago, is a columnist for the Tribune Content Agency.