Obama: concussion drove me into White House race 22 minutes ago Democrat Barack Obama joked Wednesday that the true reason he entered the White House race was concussion. "Why did I start running for president? I got hit on the head with a rock," the Illinois senator told a seven-year-old girl who questioned him on his motivation at a "town hall" meeting in Indiana. "When I woke up, I'd made my announcement and then it was too late. No, I'm teasing," Obama said to laughs.