Mr. Thompson, who represents this grape-obsessed district in Congress, is not only the industry?s foremost champion in Washington, helping it secure tax breaks, get money for pet projects like the Napa Valley Wine Train or beat back restrictions on direct sales of wine. He is also a vineyard owner, growing 20 acres of sauvignon blanc grapes at his farm north of Napa.
While plenty of lawmakers in Washington act as advocates for particular industries, Mr. Thompson is in business with some of the same companies whose agendas he promotes. His vineyard has been paid at least $500,000 since 2006 by two wineries whose executives have appealed to Congress on legislative matters.
Mr. Thompson could also benefit from his own efforts on the industry?s behalf, including a push to increase the value of grapes grown near his vineyard by seeking a special designation from the Treasury Department.
Mr. Thompson?s dual role as industry backer and grape producer has drawn some criticism, particularly from his alcohol industry rivals.
?Clearly, he has a personal interest in what he is advocating for,? said Craig Wolf, president of the Wine and Spirits Wholesalers of America, which has been in a dispute with wine producers over the past year. ?And the ethics rules in Congress say you are not supposed to do these kinds of things.?
Mr. Thompson called such claims nonsense. Any action he takes is to help the industry, he said, not his tiny vineyard, which he said made only an $18,000 profit last year.
?I?m unapologetic about going to the mat for the wine industry,? he said. ?That is my job.?
Mr. Thompson, 60, is the biggest recipient in Congress of campaign contributions from the alcoholic beverage industry, totaling more than $1.2 million during his seven terms. He is also a founder of the Congressional Wine Caucus, which has nearly 200 members who gather regularly to sample wine and talk about industry affairs.
He lives in St. Helena, a picture-postcard Napa Valley town, down the street from the elementary school he attended with future leaders in the wine industry like Mr. Mondavi. Mr. Thompson?s father worked as a vineyard foreman and his mother worked as a bookkeeper for local vineyards. Some of his closest friends ? and duck hunting companions ? are top local sellers.
His vineyard, most of which he bought in 2002 for $228,000 and which today has an assessed value of about $775,000, is about an hour north of Napa in Lake County, on a quiet road with pear and walnut orchards. One recent morning, the fog had just lifted at the vineyard, leaving the fields still covered with dew as Mr. Thompson headed out to walk his property, his khaki pant legs wet and boots muddy.
?It is looking good,? Mr. Thompson told his vineyard manager, David Weiss, impressed with a new weed-clearing machine. ?I like what I see.?
Mr. Thompson has a reputation for long hours, traveling constantly to the far corners of his sprawling district for community meetings and charity events. That and his down-to-earth manner ? he introduces himself to strangers as ?Hi, I?m Mike? ? explain in part why residents here take offense to any suggestion that his intertwined roles might raise ethical issues.
?He is the hardest-working guy I have ever met,? said Dennis Cakebread, an owner of the Cakebread Vineyard and a major campaign contributor to Mr. Thompson. ?So often people get elected, go to Washington, they get sucked in, and they kind of stay there. That is not what Mike is about.?
Many pointed out his family?s commitment to the community: his wife works as a nurse at the local hospital, one son is a deputy sheriff, the other works for the Fire Department. California?s wine country, they said, benefits from having Mr. Thompson in Washington, not the other way around.
But his relationship with the industry, at a minimum, is complicated.
The bulk of Mr. Thompson?s grapes, about 100 tons a year, have been sold since 2005 to Bonterra Vineyards, a winery in Mendocino, Calif., that relies on Mr. Thompson to produce about half its sauvignon blanc. Since last year, an additional 25 tons have been sold to Honig Vineyard of Rutherford, Calif., which blends them with grapes from Napa to produce its own sauvignon blanc.
Bonterra has paid Mr. Thompson an average of $978 a ton since 2005, a price that is somewhat higher than the Lake County average, $877 a ton during the same period. But Bonterra executives said it was in line with what they paid other independent growers.
?To paint a picture, you have to have to have a palette of colors,? said Robert Blue, Bonterra?s founding winemaker. ?Mike helps bring that.?
But Mr. Thompson?s ties to both companies ? as well as to other wineries ? go well beyond grape growing.