(FORTUNE Magazine) – The job of IRS commissioner, once a plum, is now a lemon. The outgoing collector-in-chief, Margaret Richardson, announced her resignation in January after the Treasury made clear it wanted a top corporate manager in the post rather than a tax lawyer. It even hired an executive search firm. Yet still there's no replacement. FORTUNE has learned one of the executives approached was Drew Lewis, the recently retired chairman of Union Pacific and transportation secretary under Ronald Reagan. The 65-year-old Lewis not only boasts high-level government experience but also led Union Pacific through a wrenching restructuring of the type the IRS now faces. Besides, he's a Republican and ex-chairman of the Business Roundtable--a man who could make the reviled IRS more palatable to Capitol Hill's GOP majority. But people familiar with the situation said Lewis declined the once prestigious post, something few have done. Lewis wouldn't comment, but sources say he believed the IRS's massive computer problems and the prospect of deep downsizing have made success for anyone nearly impossible.

--Jeffrey H. Birnbaum