What Trump has done is call out the establishment on years of dishonest rhetoric. Progressives often asked why so many working-class whites went against their own economic interests by supporting the GOP. The answer is that Republicans appealed to these voters on cultural grounds, subtly exploiting their resentments and fears…

The Republican Party promised — with nods, winks and dog-whistle toots — to change all of this and make everything the way it used to be . In practice, however, party leaders were compelled to deal with the world as it actually is. Hence, for example, the establishment view a couple of years ago in favor of comprehensive immigration reform.

Enter Trump, who has the temerity to point out that the party establishment says one thing but does another. He launched his campaign by calling the GOP’s bluff on immigration: If the 11 million people here without documents are really “illegal,” as the party loudly proclaims, then send them home. Other candidates were put in the position of having to explain why, after claiming that President Obama was somehow “soft” on immigration, their position on allowing the undocumented to stay is basically the same…

Trump has given voice to the ugliness and anger that the party spent years encouraging and exploiting. He let the cat out of the bag, and it’s hungry.

The party might nominate Trump, in which case the establishment will have lost all control. Or party leaders might somehow find a way to defeat him, in which case they will have lost the allegiance of much of the base. In either event, the GOP we once knew is irredeemably a thing of the past.