"Something is wrong with criminal justice in America," the senator wrote.
Finalists include Brooklyn, N.Y., Philadelphia and Columbus, Ohio.
The potential '16 hopeful will keynote the University of South Carolina's winter graduation.
He retweeted at least a dozen tweets from random supporters urging him to run for president.
“I’m doing everything consistent with a run for 2016," he said.
"You go through personal hell," the Republican senator said.
Obama said candidates probably aren't "gonna be looking at me to campaign too much."
Donors and Democratic operatives talked strategy at a confab in New York.
Rumors had been swirling that she would stop making paid appearances.
The Iowa Republican says "nobody wants" the turmoil that comes with impeachment.