President Barack Obama’s re-election campaign, looking to tap support for the president’s embrace of same-sex marriage, launched a voter drive in key electoral states on Wednesday, saying a Mitt Romney presidency would be the “ultimate deal breaker” for proponents of “marriage equality.”

The campaign’s effort to mobilize lesbian, gay, bi-sexual, and transgender voters and those who back their rights to wed is called “Obama Pride: LGBT Americans For Obama” and will combine on-the-ground operations in Pennsylvania, Colorado, Nevada, and Florida with an enhanced digital footprint.

“The President fights for our equality because he believes we are equal. Mitt Romney would fight against our equality because he believes we do not deserve it,” said Joe Solmonese, an Obama campaign co-chair and president of the Human Rights Campaign, an advocacy group. “We can not afford to go back.”

The campaign is highlighting Romney’s opposition to same-sex-marriage and his support of a federal amendment to the constitution that would define marriage as between one man and one woman. It’ll make its push during parades, phone banks, house parties, and other get-out-the-vote maneuvers.

Romney “has pledged to write discrimination into the Constitution of the United States,” Solmonese said, calling a constitutional amendment defining marriage as between a man and a woman the “ultimate deal breaker” for the LGBT community.

The campaign juxtaposed Romney’s public statements with the president’s legislative record, which includes ending the “Don’t Ask, Don’t Tell” policy that prevented gays from serving openly in the military and signing into law the Hate Crimes Prevention Act, making it a federal hate crime to assault people based on sexual orientation, gender, and gender identity.

The Democratic incumbent in early May became the first sitting president to embrace same-sex marriage, which analysts say is particularly important to voters under age 35, a voting bloc that helped lead Obama to the White House in 2008. The campaign immediately rallied around the shift, which sparked passionate debates and a money rush on both sides.

A campaign official touted the president’s commitment to the LGBT community but said voters will care more about the economy come November.

“Same-sex marriage is not the most important issue determining votes in November,” said Clo Ewing, a campaign spokeswoman.

Photo credit: President Barack Obama gestures upon arriving at Joplin Regional Airport aboard Air Force One in Missouri, May 21, 2012. REUTERS/Larry Downing