Jeff Bezos and his wife, MacKenzie, will aid the campaign to pass Referendum 74, which would legalize marriage between same-sex partners, The New York Times reports.
The top supporter of the referendum praised the contribution from the straight married couple as a "powerful message" that marriage is "a fundamental question of fairness." Zach Silk, campaign manager for Washington United for Marriage, said she had sent the Bezoses an e-mail Sunday night asking for a contribution. They responded on Tuesday.
Heterosexual executives such as Bill Gates and Steven Ballmer of Microsoft are joining wealthy gay executives as top contributors to same-sex marriage campaigns. Gates and Ballmer have each given $100,000.
Such gifts are being used to counterbalance well-funded opposition. While President Barack Obama has come out in support of same-sex unions, campaigns to approve them have been rejected in all 32 ballot measures conducted around the United States.
The Washington state campaign was spawned after Gov. Christine Gregoire signed a law in January legalizing same-sex marriage. Opponents have pledged to raise up to $4 million to defeat the law after getting enough signatures to put the legislation to a vote.