"The danger for Trump is two-fold: His declining popularity is taking a toll on his standing in the 17 states that will hold primaries between now and the end of the process in early June. Losing some of these states – or even winning fewer delegates in proportional states – makes it more difficult for Trump to secure a pre-convention majority of 1,237 delegates.
That’s where Trump’s horrific poll numbers could haunt him again: If Trump misses the threshold to win the nomination outright in bound delegates, it will be more difficult to convince unbound delegates to put him over the top if they see him as a general election disaster-in-the-making due to his high unfavorability ratings among all voters.
How bad are Trump’s image ratings? The HuffPost Pollster average of recent national polls puts Trump’s favorability at only 31 percent, while 63 percent view him unfavorably."