• But if Johnson falls short, one scenario is a coalition government with Labour's Jeremy Corbyn in charge, throwing a curveball not just to Brexit but to U.S. partnerships on foreign and national security policy.
• "The president is interested in seeing more leaders like him win elections," Heather Conley, director of the Europe Program at the Center for Strategic and International Studies in Washington, tells Axios' Margaret Talev.

The big picture: Among the hurdles between Johnson and a runaway election victory this Thursday are a polarized electorate, his own reputation for dishonesty and Trump.

Behind the scenes: Trump is politically toxic throughout much of the U.K. And Johnson, one of the few European leaders with whom he has genuinely warm relations, was careful not to get too close to Trump during last week's NATO summit in London.

• Johnson huddled with other heads of state including Justin Trudeau as the Canadian prime minister mocked Trump's rambling press conferences.
• "Boris kept his distance and was with the gang mocking the president," Nigel Farage — a Trump ally but a Johnson rival as leader of the upstart Brexit Party — tells Lawler via text. "I did not like it."

Yes, but: James Johnson, who ran Downing Street's polling under Theresa May, says focus groups suggest Trump isn't as much of a liability with British voters as he's made out to be. Johnson, the pollster, gives the Conservatives a 75% chance of a parliamentary majority.

The bottom line: Peter Westmacott, former British ambassador to the U.S., tells Lawler that even if Boris Johnson's Brexit deal passes there will be "numerous dramas throughout the course of 2020" as the U.K. negotiates its future trading relationship with the EU, while a U.S.-U.K. trade deal will take "years of hard bargaining."

Go deeper:

• Only poll to predict 2017 U.K. election result forecasts huge Boris win
• Jeremy Corbyn accuses Tories of putting NHS "up for sale" in post-Brexit U.S. trade deal
• Boris Johnson vows not to extend Brexit transition period past 2020

The big question: Will Biden move away from a posture of defending his son's honor to acknowledge and address legitimate concerns about his own judgment among some Democrats and swing voters?

• Biden told Axios' Mike Allen that Hunter did nothing wrong — but that he has not dug into what Hunter actually did while working in Ukraine.
• “I don't know what he was doing. I know he was on the board. I found out he was on the board after he was on the board and that was it,” Biden told us. 
• Asked whether he wants to get to the bottom of it, Biden said, "No. Because I trust my son."

Biden said his family will be banned from making money overseas if he wins, faulting the president's family members' government and business conflicts of interests — not Hunter’s work — for the need for a formal guardrail. 

• “They will not be engaged in any foreign business because of what's happened in this administration.”

Axios' Alexi McCammond, who spent time on Biden's Iowa bus tour this week, said after he called a man a "damn liar" at one event for making unsubstantiated claims about Hunter's work, Biden told reporters the next day that he "probably shouldn't have challenged him to pushups" and doesn't want to stoop to Trump's level in terms of engagement with critics.

Go deeper:

• Biden: Media, rivals wrong that AOC represents direction of party
• Biden: Stuttering not to blame for verbal screwups
• Biden skeptical Bloomberg will catch on

• At 73, President Donald Trump is one of America's oldest boomers.

Driving the news: The departures of Kamala Harris (55) and Steve Bullock (53) this week from the Democratic nominating contest are just the latest examples of the failures of Gen X to gain traction.

• Beto O'Rourke (47), Kirsten Gillibrand (52), Tim Ryan (46), and Seth Moulton (41) are earlier casualties.
• Hanging in the contest but at 3% or lower in national polls: Gen Xers Cory Booker (50), Julián Castro (45), Andrew Yang (44) and Michael Bennet (55). (Amy Klobuchar, 59, and John Delaney, 56, are boomers. Tulsi Gabbard, 38, is one of the oldest Millennials.)
• Harris was born in October 1964, and Bennet in November 1964, on the bubble between Gen X and boomer, but culturally they have more in common with the experiences of Gen X.

What's next: Two late entrants, who jumped in last month after concluding the Democratic field just might not have what it takes, are either boomers (Deval Patrick, 63) or from the Silent Generation (Mike Bloomberg, 77).

• Bloomberg and another candidate, boomer Tom Steyer (62), are billionaires, so they can afford to stay in the race until the convention regardless of polling.

By the numbers: Generation X generally describes people born 1965-80 — putting them between the ages of 39 and 54 — per the Pew Research Center.

• The Silent Generation covers birth years 1928-45.
• Baby Boomers were born 1946-64.
• Millennials were born 1981-96.
• Generation Z includes people born between 1997 and 2012. While some Zs can vote next November, none is yet old enough to run for president.

Why it matters: Other generations might argue, it doesn't. (Ouch!) Gen X is a smaller pack population-wise than either boomers or Millennials.

• The New York Times summed it up as a "gloomy, goofy club of forgotten middle children," while a Washington Post columnist made the case that Gen Xers have been underrated "repairers," "fixers" and "uniters."

Flashback: In cycles past, being in the age range that now covers Gen X was a sweet spot for presidential candidates.

• Bill Clinton was elected at 46. Barack Obama was 47. George W. Bush was 54. (You guessed it. They're all boomers.)

Our thought bubble: As Lelaina Pierce said, "I was really going to be somebody by the time I was 23."