Based on primary results - I think, yes, it is inconceivable that a "large portion" of the democratic voters want Clinton.
Lets say 50-55% of the voters want Clinton - how many of those voters want Clinton because she is a woman? How many want her to be a 3rd Obama term?
Let say 25% want her to be an historic 1st female president. 50% want her to be Obama's third term, and 25% really just don't like Bernie (which would be incredibly high, given his favorability ratings with the Democrats)
So, out of the democrats, 12% want her to be the first female president, 25-30% want her to continue Obama's presidency, 12% hate Bernie, and 45+% would rather have Bernie than Clinton.