Gov. Bill Ritter (D) said Monday he won't endorse a Democratic candidate for president before the Democratic National Convention in August unless there is an apparent nominee.

At the convention itself, "I'll vote my preference," Ritter said during an interview on Colorado Public Radio's "Colorado Matters" program.

Six of Colorado's 14 DNC superdelegates -- including Ritter -- are undecided.  Four have supported Barack Obama, while four say they back Hillary Clinton.

However, Brian Schaffner of the Center for Congressional and Presidential Studies at American University in Washington, D.C. projects that Ritter will vote for Obama. 

Schaffner projected how every undecided superdelegate will vote using factors such as gender, how many people in the superdelegate's state voted for John Kerry in 2004, and the percentage of the superdelegate's state that lives in an urban area.