Gay rights and free speech have quickly become salient issues in Minnesota's gubernatorial race after Target donated thousands in support of an anti-gay candidate.

The Minnesota-based retail giant is among the companies that donated to MN Forward, an independent political fund supporting anti-gay Republican candidate Tom Emmer.

Emmer, a fierce social conservative, has spoken in favor of putting a gay marriage ban in the Minnesota Constitution.

Gay rights activists in Minnesota, led by the group OutFront Minnesota, have protested the donation. And 25,000 people have joined the Facebook group "Boycott Target Until They Cease Funding Anti-Gay Politics."

Also caught in the cross-hairs are Minnesota-based electronics giant Best Buy Co., Red Wing Shoes and Polaris Industries Inc., a manufacturer of snowmobiles, all of which donated to MN Forward.

The Human Rights Campaign (HRC), the nation's largest gay advocate, published an open letter to Target and Best Buy in the Minnesota Star-Tribune calling on the companies to make amends.

"It's time to make things right," the letter says. "The very least you can do to begin rebuilding your image among fair-minded consumers is to make equivalent donations to groups that support candidates who will put all Minnesota families first and fulfill the promises of our highest ideals."

Target, which contributed the most money, $150,000, and Emmer say the donations are more about free speech than anything else.

The Republican presumptive nominee called the flap "sad" because it dampened his free speech rights.

"We're supposed to celebrate the fact that we have different perspectives," he told Fox News.

Target CEO Gregg Steinhafel said last week that his company remains committed to the gay community and that the donation had more to do with supporting business objectives such as job creation.

"Target's support of the GLBT community is unwavering, and inclusiveness remains a core value of our company," Steinhafel said in a statement.

Gay activists say Target's long history of supporting the gay community makes its decision to support Emmer even more troubling, and dismissed Emmer's claim that his or Target's free speech rights are being trampled over.

"We have the right to be able to criticize that decision [by Target] and do it publicly," Monica Meyer, of OutFront Minnesota, said.

The National Organization for Marriage (NOM), the nation's most vociferous opponent of gay marriage, has called Minnesota the next key battleground in the gay marriage debate. The group announced in May it would pour $200,000 into the state.

Leading Democrats in the race to win their party's August 10 nomination support legalizing gay marriage. A July 21 Rasmussen poll found all three hopefuls enjoying a narrow lead over Emmer.

One of those Democrats, ironically, is former Senator Mark Dayton, whose family founded Target.