Superdelegate and Iowa Democratic Chairman Scott Brennan endorsed Barack Obama on Tuesday, hours before the presidential candidate makes his first visit to Iowa since the state's precinct caucuses.
Brennan's backing brings Obama's total delegate count to 1,917, a little more than 100 delegates short of the 2,026 needed to clinch the nomination. That total includes 306.5 superdelegates, according to the latest Associated Press count.
Hillary Rodham Clinton had 1,722 delegates, including 278.5 superdelegates.
Brennan said the Illinois senator had built one of the strongest grassroots organizations ever leading up to the Iowa caucuses.
"Obama is bringing new people into the political process at historical levels, not just here in Iowa, but nationally," Brennan said during a news conference at the Iowa Democratic Party headquarters in Des Moines. "Barack Obama is going to help build the strong future of the Democratic Party."
Brennan said he initially didn't make an endorsement to create a level playing field leading up to Iowa's caucuses. The first-in-the-nation contest was held Jan. 3 and resulted in a solid win for Obama.
Brennan announced his support on a day when primaries in Kentucky and Oregon are expected to give Obama a majority of pledged delegates. Obama is scheduled to return to Iowa on Tuesday night for an outdoor rally near the state Capitol in Des Moines.
Seven of Iowa's 11 superdelegates have endorsed Obama. Three have endorsed Clinton. Sen. Tom Harkin is Iowa's only uncommitted superdelegate.
Asked why he hasn't backed a candidate, Harkin said he will maintain his neutrality until after all the state contests.
"There are a handful of states left and I believe the people in those states should weigh in before I do," Harkin said in a statement.
In response to a question, Brennan said it's unlikely Clinton will quit the race before the Democratic National Convention in August.
"Iowans like Hillary Clinton, they respect Hillary Clinton. I like her and I respect her, and it's entirely up to her whether or not she drops out," he said.