No. Cruz wouldn't have motivated disaffected voters like Trump did, would have no appeal to the working class, and may have scared progressives who protest-voted into Hillary's column due to his opposition to gay rights.
People need to keep in mind that Cruz was somewhat of a different candidate prior to Trump's entry. He had previously written an op-ed with Paul Ryan backing the TPP, he was more ambiguous on immigration than the other candidates and had room to maneuver depending upon which way the wind was blowing. If Breitbart & Co. wanted him to shift gears in their direction on that front, he may have listened to them.
Cruz, to his credit, was able to defang Huckabee/Santorum who wanted gay marriage outlawed nationally, Cruz had more of a 'state's rights' view on the issue. Cruz would've been positioned slightly differently w/o Trump, he would've been more of a Rand Paul-lite candidate (that was his original plan until Trump came along).
So, imagine a Trumpless race, w/o Trump's free media, Jeb and his money are the main factor, they are successful in keeping potential competitors at bay all the way to the convention, ensuring that no one gets to 1237. Cruz uses his delegate shenanigans to launch a coup at the convention and Jeb relents in exchange for the VP slot.
