I know what you're trying to say here, that Trump actually went up after Rubio dropped, but that 3/3 poll was a WSJ/NBC poll that consistently has been, and continues to be, low for Trump and high for eveyone including the Tasty Cake man. It was also coupled with a couple of other polls that had Trump up +9 and +15 during that same date range. somewhere in between was more accurate. We have to be careful how we use polls to support Trump especially since we're so critical how they're used to ding him.
The WSJ and Fox news is owned by Murdoch, who has an agenda against Trump big time.This poll has always been an outlier.
Three Strikes Third Time This Campaign Season NBC/WSJ Caught Promoting Agenda Polls
http://theconservativetreehouse.com/2016/02/17/three-strikes-third-time-this-campaign-season-nbcwsj-caught-promoting-agenda-polls/