A considerably better-known political analyst, former George W. Bush strategist Matthew Dowd, has observed that anti-Trump forces have comforted themselves with various “myths” during Trump’s rise, all to reassure themselves that Trump’s threat was not serious. “Summer flings, voters will get serious, ceilings, Trump won’t win a primary, organization matters — and other establishment political myths,” Dowd tweeted on Wednesday.

I asked Dowd whether the delegate count has become the latest such myth. “Yes, the delegate math rationale is now taking on the feel of all the other delusions the establishment has used to convince themselves,” Dowd responded in an email exchange. “It is possible, but only matters if Trump momentum stalls or is stopped. And that won’t happen unless he makes a major error that matters. Or someone else starts winning.”

Was Trump’s performance at Thursday night’s debate in Houston a major error that matters? Did Rubio’s aggressive takedown of Trump on healthcare amount to someone starting winning? It’s hard for pundits to anticipate what voters will think after the debate has had a few days to sink in. It won’t really be known until Super Tuesday. But whatever the fallout from the debate, the fact is, something big has to change for Rubio in just a few days.