Trump's Ballon will pop
Look, go and just view a few of these video's on Trump:
People that were scammed by the con man out of $35K for Trump "University" tuition. Just the tip of the iceberg.
If the Republican party primary doesn't pop his ballon, oh well, it will happen. Now, Rubio was really good. He's got a lot of wit, and is quick with the dagger. Where Trump is the strongest is where he attacked. On illegal immigrants and on the economy/jobs, ie Trump's job creating credo. I suspect Rubio will bounce.
Trump getting endorsements from other GOP losers does not help him, as not only does it come off as desperate, but it really tarnishes his brand as not being part of the system.