San Antonio Mayor Julian Castro will join Rep. Kathy Castor and other Florida Democrats for a canvassing effort in Tampa tomorrow as the Obama campaign opens its 100th office in the state.

"With the October 9th voter registration deadline quickly approaching, our grassroots army will be working to ensure Floridians can make their voice heard on Election Day,” Ashley Walker, Obama for America state director, said in a statement.

Castro, who delivered the keynote address at the Democration National Convention, will appear at the new South Tampa office, 3825 Henderson Boulevard, Suite 405, at 1:30 p.m.