DOVER, Del. – A divided state Senate voted Tuesday to make Delaware the 11th state in the nation to allow same-sex marriage, after hearing hours of passionate testimony from supporters and opponents.

Less than an hour after the Senate’s 12-9 vote, Democratic Gov. Jack Markell signed the measure into law.

“I do not intend to make any of you wait one moment longer,” a smiling Markell told about 200 jubilant supporters who erupted in cheers and applause following the Senate vote.

“I am elated,” said Scott Forrest, 50, of Newark, who entered into a same-sex civil union last year with his partner of almost 21 years, Kevin.

Delaware’s same-sex marriage bill was introduced in the Democrat-controlled legislature barely a year after the state began recognizing same-sex civil unions. The bill won passage two weeks ago in the state House on a 23-18 vote.

While it doesn’t give same-sex couples any more rights or benefits under Delaware law than those they have in civil unions, supporters argued same-sex couples deserve the dignity and respect of married couples. They also noted that if the U.S. Supreme Court strikes down the Defense of Marriage Act, which bars married gay couples from receiving federal benefits, civil unions would not provide protections or tax benefits under federal law to same-sex couples in Delaware.

“All couples under the law should be treated equally by their government,” Lisa Goodman told lawmakers during Tuesday’s three-hour debate. Goodman is president of Equality Delaware, a gay rights group that drafted the legislation and led the effort to get it passed.

Opponents, including scores of conservative religious leaders from across the state, argued that same-sex marriage redefines and destroys a centuries-old institution that is a building block of society.

“Let’s be careful about the concept of social evolution,” said the Rev. Leonard Klein, a Roman Catholic priest speaking on behalf of the bishop of the Diocese of Wilmington, which serves more than 200,000 Catholics in Delaware and Maryland’s Eastern Shore.

“When you remove male and female from the definition of marriage, all bets are off,” added Klein, who urged lawmakers to show an “appropriate humility” for thousands of years of human experience.

Under the bill, no new civil unions will be performed in Delaware after July 1, and existing civil unions will be converted to marriages over the next year.

The bill does not force clerics to perform same-sex marriages that conflict with their religious beliefs. But under an existing Delaware law banning discrimination based on sexual orientation, business owners who refuse to provide marriage-related services to same-sex couples for reasons of conscience could be subject to discrimination claims.