Herman Cain -- Rethinking Presidential Run

Herman Cain told his staff this morning ... he's considering dropping his bid for the presidency -- this according to the National Review.

Cain made the announcement during a conference call this morning, one day after yet another female accuser -- Ginger White -- came forward ... claiming she had a 13-year relationship with the married Republican candidate.

Cain denied the allegations during the conference call, but said, "Obviously, this is cause for reassessment."

There were four other women before White, who accused Cain of sexual harassment -- but Cain said Ginger might be the straw that breaks the camel's back ... claiming, "With this latest one, we have to do an assessment as to whether or not this is going to create too much of a cloud, in some people’s minds, as to whether or not they would be able to support us going forth."