The Note: Joe Biden in the On-Deck Circle

— -- NOTABLES

--CLINTON LOSING STEAM IN NEW NATIONAL POLL: On the heels of the Democratic National Committee summer meeting in Minneapolis today, a new Quinnipiac poll out this morning shows Hillary Clinton clocking in a 45 percent, her lowest number in a national poll during this election cycle, ABC's RYAN STRUYK reports. The new poll also shows that only 34 percent of voters say Clinton is honest and trustworthy, while six in 10 say she is not. Still, the former secretary of state holds a broad 23-point lead over Bernie Sanders.

--BIDEN WAITS IN THE ON-DECK CIRCLE: Vice President Joe Biden, who is testing the waters on a 2016 run but isn't jumping in, earned the highest favorability rating of any 2016 candidate in today's new Quinnipiac poll. Despite not being in the race, Biden garnered 18 percent support from Democratic voters, likely fueling more buzz around his potential candidacy among top Democrats and in the media. But the Vice President will be on minds in Minneapolis today: he held a conference call with DNC members on Iran yesterday.

--TRUMP'S SUPPORT HITS NEW HIGH: On the Republican side, Donald Trump's lead has stretched to its widest of the election cycle, pulling ahead of the field by 16 points in today's new poll, ABC's RYAN STRUYK reports. The real estate mogul's 28 percent support is his best of the primary season, followed by neurosurgeon Ben Carson with 12 percent and Jeb Bush, Ted Cruz and Marco Rubio tied at 7 percent. With Clinton sinking and Trump ticking higher, could we be approaching the day when Donald Trump's lead is wider than Hillary Clinton's?

--CLINTON ON EMAILS: 'I TAKE RESPONSIBILITY': On the campaign trail, Hillary Clinton took slightly more responsibility for using a private email server yesterday, but stopped short of a full apology, ABC's SHUSHANNAH WALSHE and CECILIA VEGA report. At a press conference in Ankeny, Iowa, she said, "it clearly wasn't the best choice. I should have used two emails. One personal, one for work, and I take responsibility for that decision and I want to be as transparent as possible."

--CLINTON ON GUN VIOLENCE AFTER VIRGINIA SHOOTING: Hillary Clinton seemed to get emotional when speaking about the shooting of the two journalists in Virginia yesterday, ABC's SHUSHANNAH WALSHE and ALANA ABRAMSON report. She said she was "stricken" and feels "great heartache" about what happened. She added: "I will also reiterate we have got to do something about gun violence, and I will take it on."

ANALYSIS -- ABC's RICK KLEIN: There were no jokes but there were some notes consulted when Hillary Clinton gave her latest -- and most contrite -- explanation for the email mess that's threatened to gobble up her campaign. "I take responsibility for that decision, and I want to be as transparent as possible," she said about her choice of intermingling public and private correspondence on the now-famous privately held server. The contrition comes amid new signs of the toll the story has taken on her campaign: A new Quinnipiac poll finds fewer voters viewing her as honest and trustworthy than think the same of Donald Trump. And Vice President Joe Biden has moved from backstage to the wings. According to associates of Vice President Joe Biden, the public and private signals from the White House have been pure encouragement -- a suggestion, at least to some, that there's disappointment and even resentment about how the Clinton campaign has progressed these last few months. That same poll shows Biden running as strong or stronger against major Republican candidates. It also asked respondents to offer the first word that comes into mind when they hear Clinton's name. The top three? "Liar," "dishonest," and "untrustworthy."

TODAY ON THE TRAIL with ABC's SHUSHANNAH WALSHE:

Donald Trump is back on the trail today with a morning event and possible press conference in South Carolina. Hillary Clinton is still on her break from vacation, today campaigning in the general election swing state of Ohio. She attends a grassroots "organizing meeting" at 10 am. Joe Biden spends his day behind closed doors today. Yesterday, he held a conference call with DNC members. The topic was lobbying for the Iran deal, but when asked about a possible run he said, " If I were to announce to run, I have to be able to commit to all of you that I would be able to give it my whole heart and my whole soul, and right now, both are pretty well banged up."