The GOP counter-establishment IS the GOP establishment

Tim Alberta from National Review has a great report about Ted Cruz winning the allegiance of a group of conservative factional leaders who met under the auspices of Family Research Council president Tony Perkins at a Sheraton hotel in Tysons Corner to decide on how to unite behind a single conservative candidate for the presidency. Read Alberta for the color, but the tl;dr is that once upon a time it looked like Jeb Bush would be a strong player, but as he faded in favor of Marco Rubio it came down to Rubio and Cruz, and even though there was some tough resistance to Cruz, he had the most backers from the get-go and eventually secured the supermajority. 

This is the clearest sign of some institutional support for Cruz emerging, and potentially sets the stage for him to become the GOP establishment's preferred Stop Trump candidate, even though GOP congressional leaders can't stand him.

So whose support has Cruz won? Alberta describes it as "a loose coalition of some 50 like-minded conservative leaders from around the country." 

Looking at the names he mentions, I would say it's specifically social conservative leaders associated with causes that have become a bit unfashionable in today's political climate. There's Perkins, and Alberta also names Richard Viguerie, Brian Brown, Bob Vander Plaats, James Dobson, Ken Cuccinelli, Penny Nance, Jonathan Falwell, Ken Blackwell, Kelley Shackleford, Rick Scarborough, and Henry Jackson as involved in the group.
By contrast, Alberta reports that Phyllis Schlafly, Grover Norquist, and Ralph Reed all "rejected from the outset Perkins' plot to unite the movement." 

The non-participation of Norquist, in particular, underscores the limits of this group, which does not seem to include many people focused on economic policy issues and is mostly composed of conservative leaders who see themselves — like Ted Cruz — as at odds with the party's formal leadership. In normal times, this would be the harbinger of a factional evangelical candidacy — something like the Mike Huckabee 2008 campaign or the Rick Santorum 2012 campaign — rather than a successful bid for the nomination. But the combination of establishment terror of Trump and a clearer party consensus against immigration reform than existed in 2008 may change the calculus this time around.