Googling the phrase 2016 primaries indicates that Donald Trump is the "likely Republican presidential nominee" (emphasis mine).
While Donald Trump needs 1237 delegates to secure the nomination, he currently only has 1013. However, all of his opponents (namely Cruz and Kasich) have recently dropped out of the race.
My question is, why does Google only consider him the likely nominee? Won't he, by definition, win the remaining delegates and pass the 1237 threshold? Or can something still go wrong pre-convention that takes the nomination away from Trump?