Samuel "Joe" Wurzelbacher, who rose to prominence by asking presidential candidate Barack Obama a blunt economic question in 2008, has died at age 49.
Dubbed "Joe the Plumber" by Mr Obama's rival John McCain, his name came up dozens of times during the race, making him a fixture of cable television.
Wurzelbacher had been diagnosed with pancreatic cancer. His death was confirmed on Monday by his wife.
A fundraiser for his family received over $145,000 (£115,000) as of Monday.
Video of Wurzelbacher speaking to the future president at a campaign stop was widely dissected by the media during the presidential race.
"I'm getting ready to buy a company that makes $250,000 to $280,000 a year — your new tax plan's going to tax me more, isn't it?" he asked Mr Obama.
Mr Obama's response, that his plan aimed to "spread the wealth around", led Mr McCain to invoke "Joe the Plumber" in a later debate.
Following the question, Wurzelbacher went on to campaign with Mr McCain and his running mate, Sarah Palin.
In 2012, the native of Toledo, Ohio, ran for Congress and lost in a landslide after calling for a US-Mexico border wall and for US agents to "start shooting" immigrants suspected of illegally entering the US.
He went on to sometimes court controversy as a conservative commentator, writing an open letter in 2014 to the parents of university students who died in a mass shooting saying he was "sorry you lost your child" but "as harsh as this sounds - your dead kids don't trump my Constitutional rights" to own firearms.
He is survived by his wife, Katie, and four children.
"When I met Joe he was already known by everyone else as 'Joe the Plumber' but he wrote something to me that stood out and showed me who he truly was: 'just Joe.' He was an average, honorable man trying to do great things for the country he loved so deeply after being thrust into the public eye for asking a question," his wife said in a statement sent to US media outlets.