In some ways, Hillary Clinton's situation is similar. Quinnipiac University just released polling on the presidential candidates after surveys in Colorado, Iowa and Virginia. In those three pivotal states, Clinton is the most unpopular Democrat, with net favorability (the number saying they view her favorably minus those who say they don't) low enough to rival Trump's. Here's the situation in Iowa, for example. (Similar graphs for Colorado and Virginia are at the bottom of this post.)
We've highlighted Clinton (at right), as well as Ben Carson and Scott Walker, who do well among Republicans, and Trump and Christie, who don't. This is among all voters, so a lot of the unfavorable ratings for Clinton come from Republicans (as many of the unfavorables for Trump come from Democrats).
As the focus of the Republicans'/conservative media's fire for months on end, given that she's still all-but-certain to get her party's nomination, Clinton's favorability ratings have taken a beating. Here's how her favorability from the last three Quinnipiac polls in the the three states compares to two leading Republicans, Jeb Bush and Walker.
Bush is sort of mixed. Walker is trending up. Clinton is dropping like a rock.
After Quinnipiac's April poll, we noted the correlation between how Clinton was faring against the GOP field and how her favorability in each state had changed. The picture now is slightly more nuanced, but the phenomenon is the same. Clinton has dropped in all three states; her margins in a head-to-head contest with Bush and Walker have as well.
Notice that Bush is nearly as unpopular as Clinton in Colorado, but still leads her handily in that state -- by an even wider margin than Walker, who's much more popular. Let that serve as a reminder that this is not as simple as unpopular equals losing over the long term.
In case Trump didn't already serve as a reminder of that.