The Obama campaign held a conference call this morning with Roy Romer, a former Colorado governor and DNC chairman who announced he is endorsing Obama.

Romer explained his decision during the call: "Colorado has a state convention this Saturday. ... It was obvious that it would be helpful if I make my position known. ... The more people know of superdelegates' positions, the better decisions we're going to make. ... The math is controlling. This race, I believe, is over. Senator Obama has amassed a lead...that cannot be overcome. It is time for the party to unify...and move on to the general election."

Also, washingtonpost.com reported this morning that D.C. superdelegate Anita Bonds, chair of the D.C. Democratic Party, announced her endorsement for Obama last night.

Obama won both the Colorado caucuses and Washington, D.C., primary by large margins.