The people of Illinois in effect had no one else to vote for. Skin color had nothing to do with it. "Removing" the overwhelimingly popular Jack Ryan from the race had everthing to do with it. Obama had no chance what-so-ever of beating Jack Ryan, and he knew it.
And even in US Senate race, they could have voted for Alan Keyes, if they cared at all about the unborn.
But that's the real problem in Illinois; it's apparently a state that holds babies in low regard.