Trump is getting some support from conservatives, but a big percentage of his support is shallow (e.g., based largely on name recognition) or anti-conservative. See, for example, here and here. Here's an excerpt from the second article:
"Among his supporters, a 47% plurality identifies him as 'conservative' but 30% call him 'moderate' and another 11% say he's 'liberal.' For many, it's his personality rather than his ideology that makes the difference. A 65% majority of Trump's supporters say they're willing to put their trust in his ability to figure out the issues on the fly and don't need him to be clear about specific policies he'd address if elected."
A Slate article from late July:
"But while Trump’s outsider appeal is undeniable, a closer look at the polls suggests it may also be overblown. In the last national survey conducted by Fox News, for instance, pollsters reassigned Trump supporters based on their declared second choice. The biggest winner? None other than establishment poster boy Jeb Bush, who saw his support climb by more than a third to 19 percent. (The bizarre Bush-Trump overlap can also be seen in reverse: With Jeb out, Trump’s support climbs by 3 points, the biggest jump of any member of the field.) It’s only one poll, of course, but we’ve seen similar trends in others."