The National Cathedral is seeking money to repair damage from an earthquake in 2011. (Nikki Kahn/THE WASHINGTON POST)

By its nature, historical preservation is not a popularity contest. Indeed, the industry prides itself on not bending to the latest architectural trends in deciding which buildings deserve protection.

But for properties short on funding for repairs or improvements — and in many cases visitors — drumming up a little support can’t hurt, which explains why the National Trust for Historic Preservation and the American Express Foundation are bringing a $1 million “American Idol”-inspired popularity contest to Washington this spring.

Eight years ago, the two organizations founded Partners in Preservation, a competition in which the owners and managers of historical properties try to round up points on social media in hopes of taking home a slice of $1 million put up by American Express as a prize.

The trust and foundation choose a different city every year. The first was San Francisco, followed by stops in Boston, Chicago and New Orleans, among others. Voting began in Washington April 24 and runs through May 10.

“What we want to do is identify sites that have specific, tangible restoration projects that are ready to go,” said Tim McClimon, vice president for corporate social responsibility at American Express and president of the foundation. “We want them to have projects that can be completed in, say, 18 months, and we want them to have projects that the community can identify with.”

After Washington was selected as the contest home this year, the National Trust began vetting candidates and selected 24. They span from Northern Virginia to the District and suburban Maryland, some of them tourist attractions, others little-known neighborhood institutions.

Among the better-known: Washington National Cathedral, Mount Vernon, Arlington House and the Marine Corps War Memorial. Among the lesser known: the Kennel at Aspin Hill Memorial Park in Silver Spring, a pet cemetery with “more than 50,000 animals including celebrity pets and war heroes,” and Darby Store, a Colonial Revival-era rural house and store in Beallsville, Va.

“We want some sites that are iconic sites … because that’s what draws people into the project. But we want other projects that are hidden gems for people even in their own neighborhoods,” McClimon said.

Each of the contending properties lists a project that owners would like funded and their staff and supporters use Twitter, Facebook, Instagram and other tools to build support and score points in the contest. Voting online, posting photos and tweets after visits all score points and — ideally — increases the buildings’ exposure to visitors and the organizations’ capacity for marketing through social media.

A lot of the organizations managing historical properties are thinly staffed and aren’t necessarily actively interacting with visitors and supporters online, said Stephanie Meeks, president and chief executive at the National Trust for Historic Preservation. “Most historic site management organizations are pretty small and they have a lot to do,” she said.

Every finalist wins at least $5,000, but the most popular projects have the chance to win up to $100,000. As of late last week the National Cathedral was in the lead with more than 596,000 points, topping Mount Vernon and the Greenbelt Theatre.

The cathedral is still reeling from $20 million in damage from the August 2011 earthquake that literally rang the cathedral’s bells and loosened mortar in stone joints in the building’s nave vaults and ceiling. The organization taped a YouTube video featuring mason foreman Joe Alonso to make a pitch for the 106-year-old building, which still has safety netting in place to protect against crumbling mortar.

“The National Cathedral is entrusted to all Americans, and to you,” Alonso says in the video. “Your votes for the National Cathedral will help provide funds to inspect the vaulted ceiling, repair any damage found and remove the netting, filling the cathedral once again with glorious light.”