It is a safe bet that Tom Coburn will not have a big federal building named for him. He is not likely to get a monument erected around here honoring him. He won’t be sitting for an official portrait — striking that generous pose of the longtime, greasy politicians — anytime soon.

No. The news from Sen. Tom Coburn, Oklahoma Republican, that he is retiring and will not finish his second term, will come as a huge relief to people around here and all across the sprawling federal bureaucracy.

But for America, those who cherish freedom and voters who believe in responsible, honest and limited government, one can scarcely think of a greater blow to the republic.

Mr. Coburn’s good constituents back home surely will find a satisfactory new senator. But, simply put, Tom Coburn is irreplaceable.

He is not the most visible politician in Washington. You would never catch him between Chuck Schumer and a television camera. There isn’t much pretty or flashy about the guy. He doesn’t hold forth for hours on end waxing poetic on the Senate floor about humble beginnings or overcoming personal strife or foolishness like that.

If you call him “Senator,” he might correct you and tell you to call him “Doctor.” And he is not joking.

Tom Coburn is one of the most serious, determined and hardest-working people in Congress. And he expects the same from those who work for him.

He has dedicated his time here in the federal city to rooting out wasteful spending and goring every bloated, sacred ox he could find — no matter whose party had been the patron of it. He and his staff do the really hard and tedious work of scouring budgets and expense reports to find the corrupt, wasteful, or simply duplicative spending in far-flung agencies you have never heard of. And then he calls the perpetrators up from the bowels of the bureaucracy, hauls them before his committee, and gives them a good ole bipartisan public shellacking.

Another reason Tom Coburn is something of an oddity around here is that he cannot be lumped neatly into any partisan camp. A lot of Republicans around here just love the idea of tax cuts. But the second you mention actual spending cuts, they take off running like a bunch of screaming weenies.

Mr. Coburn loves tax cuts. But he loves smart spending cuts even more. He is a true fiscal conservative in a town filled with fiscal suicide bombers.

No one in Congress today works as hard as Mr. Coburn does to reach across the aisle and coax others to join his fight for honest government and fiscal sanity.

The only successful bill Barack Obama was ever chief sponsor of during his years in the U.S. Senate was one Tom Coburn cobbled together with him. The law aims to force greater transparency on federal spending.

So, what kind of thanks does a strenuously bipartisan, serious, good-government, common-sense lawmaker get around here?

He gets investigated by the Senate ethics committee for violating the august body’s stringent rules on avoiding the appearance of conflicts of interest. His crime?

Being a dedicated doctor who refused to give up on his loyal patients and devoted nurses. For years, the committee dogged Mr. Coburn, fixated on the notion that delivering babies would somehow coerce Mr. Coburn into bribery. This charade was led by the Senate’s Javert himself, Harry “Casino” Reid — surely an expert on bribery.

After years of funhouse-mirror investigation, the Senate gave up and allowed Mr. Coburn to continue seeing patients — but only if he doesn’t charge a fee.

Unlike Mr. Reid and his “ethics” syndicate, Mr. Coburn understands that holding a private job and doing it well is a much higher calling in America than being a senator. Public service is a “service” precisely because it is such a lowly and humble task in a great, vibrant country with boundless opportunity.

Few principles were more important to the Founding Fathers, and, sadly, Mr. Coburn is one of the few in Congress who still believes it.