Barack Obama on Tuesday netted the endorsement of three prominent Republicans, including Jim Leach and Lincoln Chafee, both of whom lost their congressional seats to Democratic opponents in the 2006 mid-term elections.

The announcement boosts the ranks of so-called “Obamacans” and is likely to fuel speculation about the possibility of bigger names – such as Colin Powell, former secretary of state, and Chuck Hagel, the Republican senator for Nebraska – also endorsing the Democratic nominee.