Conservatives call Landrieu an "actress" for using a staged Senate hearing in her ad.
Sen. Brian Schatz (D-Hawaii) has continued to outraise his primary rival, Rep. Colleen Hanabusa (D-Hawaii)
The former Florida congressman was found guilty of cocaine possession.
Former Florida Gov. Jeb Bush and Sen. Rand Paul (Ky.) run a close second.
Fifty-one percent of district voters said his scandal would prevent them from voting for him.
Obama declined to say who he would prefer in 2016.
Democrats are dying to have Sebelius enter the Senate race in Kansas.
Warner is the first Democrat in five years to headline the annual Shad Planking event.
Warren has said she is not running in 2016.
The Texas senator threw his support to Oklahoma Senate candidate T.W. Shannon.