Urban Outfitters Inc. is capitalizing on a tumultuous presidential election by violating the unwritten rule of retail: Never get political.

The Philadelphia-based company, which has a history of selling controversial items, is offering a range of merchandise bashing Donald Trump, the presumptive Republican nominee. That includes a T-shirt emblazoned with the slogan "IDK NOT TRUMP THO."

The shirt is exclusive to Urban Outfitters, and the phrase - texting shorthand for "I don't know. Not Trump, though" - is also available on a mug and stickers.

Consumer brands typically avoid taking a stance on topics that might be contentious and alienate customers. But Urban Outfitters is known for offbeat products that cause offense. In recent years, it has drawn flak for selling a tapestry that resembled Nazi concentration-camp garb and a Kent State sweatshirt that looked as if it were splattered with blood.

With the anti-Trump merchandise, the retailer is taking a calculated risk, said Allen Adamson, who runs the branding firm Brand Simple Consulting.

"It is unusual for a company to step so boldly into politics, particularly in a campaign as polarizing as this one," Adamson said. But there's also "huge pressure to stand out and stand for something."

Representatives for Trump did not respond to requests for comment.

In addition to selling a "Trump 20Never" pin and a book of Trump quotations styled to look like Chinese communist leader Mao Tse-tung's Little Red Book, Urban Outfitters offers more sympathetic products featuring Hillary Clinton, the presumptive Democratic nominee.

One Clinton shirt reads "Hillary Runnin' Thangs Tour 2016."

The retailer has sold politically themed shirts in past elections, though they were typically more irreverent than negative. (A Mitt Romney shirt read "2 Legit 2 Mitt.")

Urban Outfitters began selling the "IDK NOT TRUMP" shirt after an affiliate got in touch with Dave Ross, the Los Angeles-based comedian who coined the phrase, according to a BuzzFeed News story in March. The idea stemmed from a faux campaign sign that endorsed nobody but still ruled out Trump.

Urban Outfitters made a deal with Ross to produce the merchandise, which seems to be selling briskly: Some of the shirts sold out online before being restocked.

The anti-Republican slant is at odds with chief executive officer Richard Hayne's political leanings.

Hayne, who cofounded Urban Outfitters in 1970, has a history of donating to mainstream Republican candidates, including a contribution to the Romney campaign in 2012, according to Federal Election Commission records.

In an email, Urban Outfitters said it "respects the viewpoints of all customers and employees and does not take positions in electoral politics." The company declined to comment on personal donations by employees.

"Our product selection is largely driven by the demand of our customers and artistic partnerships," Urban Outfitters said.

According to a recent New York Times/CBS News poll, Trump and Clinton are tied at 40 percent nationally in a head-to-head contest. But Clinton is more popular than Trump when it comes to millennials, a key demographic for Urban Outfitters.

"Things have changed in the world of brands, particularly brands that appeal to younger, more millennial types," said Doug Usher, a managing partner at political consulting firm Purple Strategies. "They are looking to share a more intimate brand experience."