Byron York at the Washington Examiner writes:
This weekend was an inflection point in the Republican presidential race — a moment in which some significant part of the GOP establishment came out of denial and realized Donald Trump might well become their party's nominee.
"The Republican establishment, for the first time, is saying, off the record, this guy can win," noted Joe Scarborough on MSNBC Monday morning. "I've heard that from everybody. I don't hear anybody saying he can't win the nomination anymore."
That doesn't mean Republicans have made their peace with a Trump victory. On the contrary — some are preparing to do whatever it takes to bring him down. Which could lead to an extraordinary scenario in which GOP stalwarts go to war to destroy their own party's likely nominee....
The triggers for the anti-Trump onslaught would likely be: 1) if next month arrives with Trump still in the lead, and 2) if Trump begins airing his own ads. "Once that starts, you'll see a lot of people saying we've waited long enough," notes McIntosh.