An obstreperous obstetrician: Dr No retires AS RETIREMENTS and primary contests have chipped centrists away from Congress one by one, usually to be replaced with an ideologically purer lawmaker, voting in the House and the Senate has become drearily predictable. Know where someone stands on gay marriage and you probably know what he thinks about tax rises and Obamacare. Tom Coburn, who announced his retirement from the Senate on January 16th, after a recurrence of the cancer he has been fighting for a while, was pleasingly hard to read. Mr Coburn has been a hero to conservatives for opposing abortion, denying climate change, opposing gun control and attacking wasteful spending. He also opposed George Bush's tax cuts because they were unfunded, has a warm relationship with Barack Obama, who is often suspected by lawmakers of being incapable of such a thing, and put his name to bipartisan compromises on eliminating the deficit and reforming immigration. "I love the man," Mr Coburn once said of Barack Obama, " I don't want him to be president." Most careers in conservative politics, where purity is highly valued, would not survive a public declaration of love for the president, let alone a professed willingness to raise taxes to plug the deficit. Mr Coburn got away with it because he never seemed to care about his career very much. Candidates who fight election to national office are obliged to claim to their electorates back home that they are not like everybody else in the capital. Mr Coburn made a more credible Mr Smith in Washington than most. This was partly because he is a doctor from a small Oklahoma town, albeit one who had once enjoyed a successful career as a businessman in Virginia. When he first arrived in the House, Mr Coburn became known for producing slides on Capitol Hill showing gruesome examples of sexually-transmitted diseases. It is also because Mr Coburn set himself a limit of three terms in the House and then two in the Senate, an act of self-denial which he says kept him from becoming an insider and freed him to say what he wanted. What he most wanted to say was that the government wastes taxpayers" money. "[He] is like an imam at a pig roast: He sees pork everywhere, and he doesn't like it," mused Dana Milbank of the Washington Post. His latest annual publication on government waste singled out $297m spent on an unused army blimp and $432m on new air force planes that will not be flown, as well as less expensive absurdities like the $3m NASA spent studying Congress. He hated subsidies for rich farmers. "It is the height of hypocrisy for politicians to complain about tax rates for millionaires while ignoring spending programmes for millionaires," he told the Oklahoman. He was often reminded that these items were dwarfed by the funding gaps faced by the big entitlement programs, Social Security, Medicare and Medicaid, but thought cutting waste would be a good place to start. He attempted to hold up funding for the relief of Hurricane Sandy because the bill contained millions of dollars for fisheries thousands of miles away. He was the fiercest critic of the earmark in the federal budget to build a "Bridge to Nowhere" in Alaska in 2005, arguing that the money would be better spent on repairs following Hurricane Katrina. Mr Coburn's attacks on federal profligacy won him some friends but lost him plenty as well. The Senate ethics committee hounded him - absurdly - for the "conflict of interest" of delivering babies back home in Oklahoma in his spare time, though he charged only enough to cover his expenses. Partly as a result of Mr Coburn's efforts, congressional earmarks were prohibited in 2010. Not everyone is pleased about this. One of the many reasons that it is hard to get bills through Congress is that it is no longer possible to buy the votes of hostile members with pork. Mr Coburn would consider this objection to be just another defence of business as usual, a recipe for running up yet more debt to be paid back by his grandchildren, with whom he plans to spend his remaining time.