Standing in his way is an unprecedented unfavorability rating that GOP delegates will be watching closely as the campaign moves toward the convention in late July.

Politico:

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.

That’s a notable decline from late January, on the eve of the first votes in the GOP nominating process, when Trump’s average favorability rating was 37 percent, with 57 percent viewing him unfavorably.

Trump is hardly alone: Hillary Clinton and Ted Cruz are also viewed unfavorably by majorities of Americans, according to polling averages. Only John Kasich and Bernie Sanders – both of whom haven’t faced many negative attacks from either party – have positive image ratings.

Among Republicans, Trump’s numbers aren’t stellar, but they have been durable – even as the other GOP candidates have trained their fire on him. Polls earlier this month from CNN/ORC and Quinnipiac University show Trump’s overall favorability rating tanking, but the figures are virtually unchanged among Republicans: A little more than 60 percent view him favorably, and about a third have an unfavorable opinion of him.

But the remainder of Republican primaries – which resume next week in Wisconsin – will be held at the state level. And in a three-way race with Cruz and Kasich, the forces aiming to halt Trump’s march to the nomination will continue to chip away further at Trump’s image.

Some of the anti-Trump groups have chosen to target female Republicans, betting that Trump’s past – and some current – statements about women would alienate those voters. Data from the states that have already voted bear that out: Trump has run, on average, 7 points better among male voters in the 17 states where there have been entrance or exit polls, than among female voters.