Most of Romney's staff learned of the planned announcement during a 10 p.m. EDT conference call Friday about an hour before the campaign issued a statement. The identity of Romney's pick was not disclosed during the call. The campaign had promised that first news of the selection would be delivered via a phone app.
Earlier in the day, Romney's campaign briefed reporters on the bus tour without mention of the impending vice presidential announcement.
The tour will take Romney through North Carolina, Virginia, Florida and Ohio. All are battlegrounds where Obama won in 2008. They hold 75 electoral votes combined, of the 270 needed to win the election.