A spate of polls taken over the weekend show Hillary Clinton enjoying a healthy bounce coming out of the Democratic National Convention. This is to be expected. What is unusual is that the Democratic party is substantially more unified than the Republican party. Indeed, the GOP electorate looks to be dangerously fractured.
Since the DNC, three live-operator, major media polls have been conducted—by CBS, CNN, and Fox News. On average, they show Clinton leading Donald Trump in a two-way race by eight points. As a point of comparison, those three polls showed Barack Obama with an average lead of five points over Mitt Romney immediately after the 2012 Democratic convention.
So, Trump is in worse shape at this point in the cycle than Romney was, although he also has an extra month of campaigning (as the conventions finished up over Labor Day in 2012). Trump's challenge, however, is made more difficult because of the fractured state of the Republican party. Indeed, all three pollsters find that the GOP is much more divided than the Democrats, along a wide swath of queries.
Consider first vote choice by party identification. What percentage of Democrats are planning to vote Clinton, compared to the percentage of Republicans planning to vote Trump?

Clearly, the DNC was better at unifying the Democrats than the RNC was at unifying Republicans. Clinton's support from Democrats is on average 9 points higher than Trump's support from Republicans.
The same is true of favorable ratings.

Again, these are bad numbers for Trump. His favorable rating is just 70 percent on average in these polls, compared to 82 percent for Clinton. That's a 12-point difference.
Bad as those numbers are for Trump, they get worse when voters focus on the specifics.
Fox asked voters whom they trust on key issues. On item after item, Democrats are more likely to trust Clinton than Republicans trust Trump.

The good news for Trump is that on some of the most salient issues—the economy, terrorism, and ISIS—Republicans trust him about as much, if not more than Democrats trust Clinton. Still, this is a wide swath of issues where GOP voters are substantially more skeptical of their nominee than Democrats are of theirs. Note in particular Republican views on Trump regarding race relations—just 64 percent trust him, which is hardly surprising considering some of his outrageous comments. And on managing the nuclear arsenal—which is a threshold issue for most Americans—Trump registers trust from an anemic 68 percent of Republican voters.

The story is much the same for candidate qualities. Fox and CNN asked a battery of questions about the public's views of each candidate—and again, Democrats are more positive about their nominee than Republicans are about theirs.

The only issue where Trump even comes close to Clinton is on trust, and here the differences are well within the margin of error. Otherwise, Democrats have a substantially more positive view of Clinton as a person than Republicans do of Trump.
Many Republicans are aware of the divide within their party, and are relatively pessimistic that it will be bridged before November.

As you can see, Democrats are not quite as unified now as they were prior to the DNC in 2008. Nevertheless, overall they are as optimistic that their wounds will be healed. Republicans, on the other hand, are terribly divided—and nearly one-third believe that the divide is hopelessly wide.
This is a debacle for the Republican party. As a matter of historical perspective, the GOP has not been this internally split since at least 1976, and probably not since 1964. It is difficult to imagine a party winning in November if its own voters cannot unify behind its nominee.