(CNN) -- North Carolina's newly approved constitutional amendment banning same-sex marriage has sparked an effort to convince the Democratic Party to move its upcoming national convention somewhere else.
An online petition launched after Tuesday's referendum on Amendment 1 calls on the party to abandon plans to hold its September 3-7 convention in Charlotte. The petition urges Democrats to host their gathering in "a state that upholds values of equality and liberty."
But Democratic officials say that's not going to happen, even though President Barack Obama -- who will accept the party's nomination for a second term in Charlotte -- announced Wednesday that he supports allowing gays and lesbians to legally marry.
"The convention is staying in Charlotte," Democratic National Convention Committee spokeswoman Kristie Greco told CNN.
The petition was posted on Change.org, a site that is used as an open platform where anyone can start a petition. The group behind the petition, New York-based Gay Marriage USA, does not appear to have much of an existence beyond a Facebook page, said Michael Jones, Change.org's deputy campaign director.
Amendment 1 passed with 61% approval Tuesday, making North Carolina the 31st state to put a ban on same-sex marriages into its charter. Supporters said it was necessary even though state law already banned the practice in order to ward off future legal challenges, but opponents warned that it would have unintended consequences for issues such as child custody and the prosecution of domestic violence.
Hosting a national party convention is a massive undertaking. The Democrats are trying to raise $37 million to put on their show, which is expected to draw tens of thousands of people and bring in between $150-200 million, Charlotte's tourism office estimates.
In a statement to CNN, Charlotte Mayor Anthony Foxx said his city "is going to put on a great convention. That was true a month ago, and that's true today."