LAS VEGAS-Nevada's Attorney General, Catherine Cortez-Masto, has endorsed Ill. Sen. Barack Obama for the Democrats' presidential nominee.

Cortez-Masto's endorsement came just after 7 p.m. PDT, as polls closed in Montana.

"It is now time for the Democratic Party to unite behind one candidate," said Cortez-Masto announcing the endorsement. "Through a unified Party we will defeat John McCain in November.  I look forward to working with Senator Obama to create positive change for the citizens of Nevada and the United States."

With her endorsement, Obama has now secured four of Nevada's nine superdelegates to the Democratic National Convention to be held in Denver in August.

The other Nevada superdelegates to endorse Obama include Nevada Senate Minority Leader Steven Horsford, state Democratic Party first vice-chair Theresa Benitez-Thompson and former Clark County Commissioner Yvonne Atkinson Gates.

Two Nevada superdelegates, U.S. Rep. Shelley Berkley and state Sen. Dina Titus, have previously endorsed N.Y. Sen. Hillary Clinton for the nomination.

With this endorsement, only U.S. Senate Majority Leader Harry Reid, state Democratic Party Chairman Sam Lieberman, and add-on delegate Rusty McAllister remain as uncommitted Nevada superdelegates.