MARTINSVILLE, Va. (AP) -- Democrat Barack Obama is sounding tough populist themes on the campaign trail, pledging to create union jobs to build energy-efficient cars and to end tax breaks for
corporations that ship jobs overseas.

Obama is giving no hint of when to expect the announcement of
his vice presidential choice.

The Democratic hopeful is on a bus tour in Virginia, a state
that has favored Republicans in recent presidential elections but
is viewed as a battleground this year.

In Martinsville on Wednesday, Obama renewed his warning that
Republicans would try to scare voters about his background.

Obama is traveling with former Virginia Gov. Mark Warner, who
will serve as the keynote speaker at the party's convention in
Denver.