Rubio going after Trump shows that he is not afraid to take on an adversary. I think that is why Trump is so attractive as a candidate. If Rubio can shoe that he has guts, he could gain more recognition and rise above the other candidates. Republicans need someone other than Trump.
Yes, Rubio's latest debate performance will likely energize his candidacy. In the debate, Rubio was able to show that when necessary he can and will fight to be heard. He also showed that he has the ability to take on Donald Trump, something that has not really happened so far in the campaign.
Senator Rubio's recent debate performance will provide a spark to his presidential candidacy. He showed fire in going after his competitors, particularly Donald Trump. This will energize his base. He also showed energy on the campaign trail. The anti-Trump vote seems ready to rally behind Rubio. He will need to prove it is not a short-lived boost.
I don't think Rubio can energize his candidacy even if he became the energizer bunny. Trump's lead is too big and no matter what anyone does, Trump is going to win. It's time the rest of the candidates understood this and went into damage control mode. They can always try running again in four or eight years' time.