MANCHESTER, N.H. — A week ago, it looked like the stars were aligning for Marco Rubio. Now, as New Hampshire holds its pivotal primary on Tuesday, the Republican presidential contender has to hope the sky does not come crashing down on him.After a surprisingly strong third-place showing in last week’s Iowa caucuses, Rubio came into New Hampshire hoping for a top-tier finish in the state to buttress his argument he is the candidate around whom the party establishment should rally.But a debate performance on Saturday night that was widely mocked by Republicans and Democrats as well as legions on social media might have changed the equation for the U.S.