Essential Politics: A fresh start for Donald Trump, or more of the same-old?

August used to be a leisurely time in presidential politics, a chance for candidates and others in the traveling campaign circus to retire to the beach or mountains and rest up for the final sprint to November, starting on Labor Day.

No more.

The round-the-clock news cycle and bottomless maw of social media make the notion of a summer respite seem as antiquated and old-timey as straw boaters and torch-light parades.

Good afternoon, I’m Mark Z. Barabak, filling in for Washington Bureau Chief David Lauter. Welcome to the Friday edition of our Essential Politics newsletter, in which we look back at the events of the week in the presidential contest and highlight some particularly insightful stories.

While the presidential candidates and their running mates kept up a brisk schedule of coast-to-coast appearances, the biggest news of the week was yet another shake-up in Donald Trump’s troubled presidential campaign.

Polls in key battleground states show that Trump’s already difficult climb to the White House has grown considerably steeper after several weeks of self-generated controversy. The response of the Manhattan business mogul, never one to bow to political convention, was to double down on what has proved so problematic.

TROUBLES FOR TRUMP

As Noah Bierman pointed out, the demotion of seasoned campaign veteran Paul Manafort, who left Trump’s campaign Friday, and the hiring of Stephen K. Bannon, the head of the pugnacious Breitbart News website, signals Trump’s intention to continue his brawling, unrestrained ways. Cue Frank Sinatra: Come Nov. 8, win or lose, Trump will be able to say he did it is his way.

Speaking of unconventional, Don Lee visited with one of Trump’s economic advisors, a UC Irvine professor and four-time Democratic political candidate, Peter Navarro, who has never met the GOP nominee or even spoken with him on the telephone.

Looking back, Bierman paired with Joe Tanfani for an examination of young Donald Trump’s start in the real estate business, (which was helped along nicely with a big assist from his rich father.) Even then, the hallmarks of Trump’s presidential run were plainly visible, including allegations of racial insensitivity and an elbows-out approach to dealing with opponents.

Turning back to 2016, Lisa Mascaro reported from New Hampshire on concerns that Trump’s sinking fortunes could drag down other Republicans running in November and possibly cost the GOP control of the U.S. Senate. Republican incumbent Kelly Ayotte is locked in one of the country’s closest Senate contests, against Democratic N.H. Gov. Maggie Hassan, and Trump hasn’t made Ayotte’s life, or campaign, any easier.

And with shades of “Dr. Strangelove,” Evan Halper reported how Trump’s loose talk has elevated discussion of nuclear weapons and the possibility of nuclear war to the highest level in decades.

NOT ALL ROSES FOR CLINTON

Looking beyond the top-line, or horse-race, numbers, Cathleen Decker did a deep dive on the USC Dornsife/L.A. Times tracking poll and found several structural shifts that are working to Democratic presidential candidate Hillary Clinton’s advantage.

Meantime, Tracy Wilkinson, exploring Clinton’s years as secretary of State, finds her tenure helping lead the nation’s foreign policy is not the unalloyed political asset it once was.

And in the steady drip-drip-drip surrounding Clinton’s use of a private email server, the FBI turned over to Congress classified documents explaining prosecutors’ decision not to pursue criminal charges against the Democratic standard-bearer.

WHAT MIGHT HAVE BEEN

Vice President Joe Biden thought long and hard about running for president — a job he twice sought — before making way for Clinton. Ever the good party soldier, he appeared this week with the Democratic nominee at a stop in his hometown of Scranton, Pa. Michael Memoli was there as Biden proclaimed: “She gets it,” vouching for Clinton’s working-class cred.

A LATE START AND A MISSED DEADLINE

Evan McMullin, the former CIA counter-terrorism officer who last week launched a late independent campaign for the presidency, did not meet California’s deadline to submit nomination papers signed by 178,039 registered voters.

WHAT WE’RE READING

The Pew Research Center offers some of the best political analysis around, going well beyond who’s-up-and-who’s-down polling to parse various demographic groups and plumb what’s on voters’ minds. This week, the center released a nationwide survey that found Clinton and Trump supporters view the past and future in strikingly different ways. Those findings and much more are available here.

CAN’T GET ENOUGH CLINTON & TRUMP?

Everything you ever wanted to know about the two major-party nominees is here and here. And check our daily USC Dornsife/Los Angeles Times tracking poll at the top of the politics page.

LOGISTICS

If you like this newsletter, tell your friends and family to sign up. It’s free! Did someone forward you this? You can sign up here for delivery straight to your email in-box.

That wraps up this week’s summary. My colleague Christina Bellantoni will be back Monday with the weekday edition of Essential Politics. Until then, keep track of all the developments in the 2016 campaign with our Trail Guide, at our Politics page and on Twitter @latimespolitics.

Comments, suggestions, news tips? Send them along to politics@latimes.com.