Poor David Vitter.

OK, maybe that is overstating things. After all, Vitter is a member of the U.S. Senate — sometimes called the world’s most exclusive club — and he’s the frontrunner to win election this fall as governor of Louisiana, which isn’t a bad job, either.

But he’s been roughed up a bit in the public arena lately.

Politico, the Washington website and newspaper, said last week that in the “chummy confines” of the Senate, Vitter “has emerged as one of the most disliked members.” A writer for Salon, an online outlet disposed to antipathy to conservative Republicans such as Vitter, wrote a column headlined, “Everybody hates David Vitter: How the wingnut managed to tee off everyone in Washington.” Even the second-largest newspaper in his home state chimed in with an article about his propensity to “ruffle feathers.”

A catalyst for the Vitter-bashing was a vote last month in the Senate Small Business and Entrepreneurship Committee, which Vitter chairs, on a dispute connected to the so-called exemption for Congress from the Affordable Care Act. The ACA, better known as “Obamacare,” is the signature legislative achievement of Democratic President Barack Obama, and it has drawn relentless Republican criticism since it passed Congress without a single Republican vote in 2010.

Vitter’s motion to subpoena documents connected to the health care law exemption was defeated 14-5. The minority Democrats on the committee voted “no,” as expected. More surprising was that five of Vitter’s fellow Republicans on the committee joined in rejecting him.

The issue has its roots in 2010, when the health law was working its way through Congress. A Republican amendment required the federal government to stop offering members of Congress and their staffs the governmentwide Federal Employee Health Benefits Plan — a typical workplace plan, with the employer paying about 75 percent of health coverage premiums and the employee paying the rest — but instead to “make available” only plans marketed through the health law’s health insurance exchanges.

That put the members and their staffs on the spot: Unlike every other large employer in the country, it appeared that, under the law, theirs could not offer them a standard workplace health plan and pick up most of the tab.

Enter the Obama administration, via the federal Office of Personnel Management. OPM promulgated a rule that said the government would continue to pay its share of the affected employees’ coverage provided they purchased it through the District of Columbia’s ACA small-business exchange. Published news accounts have said the workaround was devised in consultation with Republican congressional leaders.

Vitter thinks the arrangement is illegal, and he has pressed stubbornly, for years, to overturn it, despite resistance from both Democrats and Republicans. He is deaf to his colleagues’ arguments that they and their staff members simply receive benefits enjoyed by most working Americans.

“Before we get to policy arguments, I think we should be following the law,” he says. “I have a big problem with just ignoring the law because it’s inconvenient.”

In any case, administrators with the House and the Senate duly applied to the D.C. exchange for enrollment of members and staffers — and close to 15,000 signed up.

But there’s a catch: The D.C. small-business exchange is supposed to be limited to small businesses, defined as those with no more than 50 employees. When the actual applications that Congress submitted came to light as a result of a freedom-of-information request by a conservative legal advocacy group, it turned out that whoever filled out the forms said the workforce in each chamber numbered 45 and that the employer was a local government — both patently false representations.

On the released documents, the names of the people who submitted them were blacked out. Vitter wanted his committee to issue a subpoena to get the complete versions of the applications, in order to identify who is responsible for entering the false information. No such luck.

Vitter’s critics say he’s grandstanding, with an eye on the governor’s race. And the controversy has led some conservative groups to rally to his side. But given how remote the issue is from Louisiana and its relative insignificance, it’s not clear how many votes his stand on principle would get him.

It could be that is just the way Vitter is: a stickler for the rules, even if that makes him a contrarian. Everyone’s high school class included at least one kid like that.

Gregory Roberts is chief of The Advocate Washington bureau. His email address is groberts@the advocate.com, and he is on Twitter, @GregRobertsDC. For more coverage of national government and politics, follow The Advocate Politics Blog at http://blogs.theadvocate.com/politicsblog/.