JOSH BARRO: This is the weirdest campaign in my lifetime, and Trump's lousy debate won't hurt him
If GOP frontrunner Donald Trump wins Louisiana and other upcoming states by the same margin that he won on Super Tuesday, Barro says, the race will essentially be over.
Trump will win enough delegates to take the nomination this spring, long before the Republican convention in July. That would eliminate the last hope of the Republican establishment to stop Trump - a so-called "brokered convention" in which no candidate gets enough delegates to clear the nomination hurdle, and the candidate is chosen at the convention.
Former Tennessee Senator Harold Ford, who joined Barro on the show, thinks Trump was wounded this week by Mitt Romney's roundhouse attack.
Barro is unconvinced.