NEW : Sen. David Vitter resumes work on Capitol Hill . NE : According to ` ` ' ' , '' he tries to keep low profile . NEW : Conservative talk to fellow Republicans at lunch . NE : Journalists seeking Vitter cause disruption in a committee meeting .
NEW : Sen. David Vitter resumes work on Capitol Hill . NEW : Linked to `` D.C. Madam , '' he tries to keep low profile . NEW : Conservative apologizes to fellow Republicans at lunch . NEW : Journalists seeking Vitter cause disruption in Senate committee meeting .