Donald Trump has surged to the top of the Republican field based not only on outsider status, but immigration.

Specifically, frustration and anger regarding illegal alien criminals. Early in his surge I wrote:

But something happened on the way to the denunciations and purges [of Trump]. Kate Steinle was murdered in San Francisco, a sanctuary city. Steinle was killed in broad daylight on a popular pedestrian pier in a business and tourist district, by an illegal immigrant with a long criminal record who had been deported five times and recently was released from custody….

In the wake of the murder of Kate Steinle, many Republican candidates have denounced the sanctuary-cities agenda. There is talk of withholding funding from cities that refuse to cooperate with federal immigration authorities. But who among the Republican candidates has stood side by side with the families who have lost loved ones to illegal-immigrant criminals?

Trump did….”

Now Trump is thumping his favorite target, Jeb Bush, with the issue in a brutal new Instagram Ad:

This hits Jeb where it hurts.

Just like the Willie Horton ad against Michael Dukakis.

And the thing is, it can be used against Democrats just as easily, using the words of sanctuary cities supporters.

Trump is demonstrating not just showmanship, but digital political savvy.