Didier - a Tea Party Republican and former NFL player - is asking supporters to submit their names, ZIP codes and email addresses at his website so they can get updates from his campaign. People who do that will be entered as contestants to win one of two pistols or a military-style rifle.
Didier, who is running in a crowded field for the central Washington seat, says the contest illustrates his unwavering support for the Second Amendment.
The drawing will be held when the campaign receives 10,000 "likes" on Facebook and/or "follows" on Twitter, or on July 4, whichever comes first, according to Didier's website.
The Eltopia farmer's campaign did not immediately return a telephone call from The Associated Press seeking comment. Didier played for the Washington Redskins in the 1980s.
A letter from the candidate on his website is addressed: "Dear Fellow Freedom Fighter."
"As a farmer, I like to think my campaign is sowing the seeds of freedom," the letter says. "The Second Amendment is the one that protects and guarantees all of our other freedoms."
Such gun contests have become a popular tool for GOP candidates this year.
Democrat Estakio Beltran of Yakima questioned the giveaway in light of the June 5 shooting at Seattle Pacific University that left one person dead and two wounded.
"I am a strong upholder of the Constitution and fully support the Second Amendment rights of all Americans," Beltran told the Tri-City Herald. "However, as a congressional candidate, I am sensitive to the grief that many here in Washington may be feeling as a result of recent tragedies."
The prizes are two Ruger 2300 LC9 pistols and a DB-15 S rifle, including a 30-round clip with ammunition, Didier's website said. Winners will have to follow all laws, including being of legal age and going through a background check.
A total of 12 candidates - including Republicans, Democrats and independents - are running in the Aug. 5 primary in a district that hasn't elected a Democrat since 1992.