Yes. I think trump has a bigger popular mandate than any othe republican candidate at this point.Trump can claim the "will of the people" mantle far more than any other candidate (or potential nominee). There's simply no denying that.
Now, in a non-Trump primary, would the votes have shaken out differently? Yes, and that very likely would have resulted in a Jeb Bush nomination, from an even weaker plurality that Trump at his weakest - because that's exactly the outcome this primary process was designed to produce.
But a more representative process would consider the public opinion of all the candidates. Trump was the most popular first choice but people either like him or they don't. I doubt he would have been many people's second choice or third choice, fourth, fifth. In the ranked polling I did on INGO, granted, Cruz won handily, but Trump got a lot of first place and last place votes. He ended up middle of the pack because he wasn't very popular.