Tuesday Afternoon Reading: Iowa Superdelegate Endorses Obama

• The Des Moines Register reports that Iowa superdelegate Richard Machacek, a farmer from Winthrop, endorsed Obama this morning.
• Obama criticizes the Supreme Court's ruling that Indiana's voter ID law is constitutional.
• Blogging for the San Francisco Chronicle, Carolyn Lochhead explains why Indiana is a must win for Obama.
• The Christian Science Monitor identifies three cities they believe are critical for Democrats in Indiana.