Mary Cheney, daughter of former Vice President Dick Cheney, has married her longtime partner, Heather Poe.

In a statement, Cheney and his wife, Lynne, said the couple got married in Washington on Friday. The Cheneys said the two had been in a committed relationship for many years and they were delighted that they could take advantage of the "opportunity to have the relationship recognized." The District of Columbia and six states - Connecticut, Iowa, Massachusetts, New Hampshire, New York and Vermont - have legalized gay marriage.

Mary Cheney and Poe have two children.

In the 2004 election, Republicans backing the ticket of President George W. Bush and Cheney pushed for state ballot initiatives rejecting gay marriage. More recently, President Barack Obama expressed his support for same-sex marriage.