Rubio is touting his electability in his last ad before the Iowa caucuses.
"At times, this presidential campaign has been downright hard to watch," a new ad says.
The Texas senator is hitting Trump for his support of eminent domain.
The 2016 hopeful accuses his rival of "spending millions on false attacks."
Former president tells New Hamsphire voters "we need you" in the new video.
Bush's campaign has accused Rubio of missing an important security briefing.
One veteran says Obama needed "training wheels" as commander in chief.
The video highlights Trump's remarks about Muslims and illegal immigrants.
Bradford Richardson 11/06/15 11:42 AM EST
The ad targets Clinton's remark that the VA scandal had "not been as widespread" as feared.
"And the working class gets stuck with the tab."