Oh I have no doubt that many did. The (R) nomination was wide-open for the first month (with a whopping 17 candidates in the race all diluting each other's votes).  And the (D) nomination was considered a slam dunk for Hillary for a year leading up to the primaries, and through the first month of them.  

It wasn't until March 5 (about 20 primaries into the race) that it suddenly started becoming a race on the (D) side, when Bernie surprised with 5 primary wins that week.  By then, Trump had taken control of the (R) delegate count by winning most of the early states, most of which were open primaries.  Nearly all the national focus was on the (R) side for that first month, anxious to see who would face Hillary in the general election.