WASHINGTON  After about two dozen years in Congress, Representative Billy Tauzin of Louisiana was after bigger game  the giant, 200-pound whitetail deer that run through the area of south Texas that hunters call the Golden Triangle.

So in 2003 Mr. Tauzin, then chairman of the powerful energy and commerce committee, made a deal. Though still on a modest Congressional salary, he paid more than $1 million for a 1,500-acre ranch there. And he invited a dozen friends  mostly executives and lobbyists with interests before his committee  to cover its mortgage by paying him dues as members of a new hunting club. It did business as Cajun Creek L.L.C., based in the Baton Rouge office of a lobbyist who was a member.

Now, seven years later, Mr. Tauzin’s friends say, it is to his Texas ranch that Mr. Tauzin, 66, will retreat, to contemplate the apparent collapse of the grandest in a career of fearless deals  a pact to trade the drug industry’s political support for favorable terms under President Obama’s proposed health care overhaul.

Mr. Tauzin is leaving his $2 million-a-year job as the top lobbyist for the drug industry amid complaints from drug makers that he bargained away their profits too cheaply, spent too much in his $150 million advertising campaign to sell the overhaul and miscalculated in his assessment that the passage of the legislation was all but inevitable.