Hillary Clinton maintains a five-point lead in a new Washington Post-ABC News poll, but it's got some potential warning signs for Clinton about what lies ahead.

Specifically, as Scott Clement and Dan Balz note: The poll shows Clinton voters are less enthusiastic about voting for her than Trump supporters are about voting for him.

About 8 in 10 say they are at least somewhat enthusiastic about voting for each candidate. But while 46 percent of Trump voters are "very" enthusiastic about voting for him, just 33 percent of Clinton voters say the same of their candidate.

What's more, 93 percent of Trump voters say they're certain to vote in November, as compared to just 80 percent of Clinton voters. And Trump voters are paying closer attention to the election (61 percent following it "very closely") than Clinton voters (45 percent) -- another potential sign of more Trump enthusiasm.

But exactly why? Part of the reason for this enthusiasm gap appears to be that Clinton voters see real flaws in their candidate.

The poll shows fully 57 percent of Clinton voters say their candidate is "too willing to bend the rules." Another 34 percent disapprove of Clinton's handling of her email problems, 31 percent are concerned about potential conflicts of interest with the Clinton Foundation, 29 percent say she did special favors for donors as secretary of state, and 27 percent say she's not honest and trustworthy.

Trump voters don't see such large liabilities with their candidate. The only problems so many Trump voters are concerned about are his inconsistencies (35 percent) and his immigration stance (24 percent).

In other words, it appears that Clinton voters are more down on their candidate than Republicans are right now.

Whether that actually matters come November is another question, of course. Clinton would certainly love for her voters to be excited about her, but American elections often aren't just -- or even mostly -- about voting for someone. They're about voting against someone or something.

And in Trump, Democrats certainly have a very capable bogeyman. Which is why you see Clinton pressing the case that Trump is stoking racism, sexism, homophobia, and Islamophobia.

While she might have taken it further than she intended this weekend -- she said she regretted saying "half" of Trump supporters were in one of these "baskets of deplorables" -- this is clearly a major part of her campaign and will be going forward. And it's all about making sure people turn out to vote against Trump, if not for her.

But at least for now, that argument doesn't have Clinton voters saying they're as enthusiastic or certain to vote as Trump voters. And that's got to be at least slightly concerning for the Clinton campaign, despite their continued lead.