Just when you thought it was safe to go back in the water. Donald Trump is running for president again. That was not a prospect Bob Woodward had to deal with when Richard Nixon resigned in 1974, after Woodward and his Washington Post colleague Carl Bernstein cracked open the Watergate scandal. “Our long national nightmare is over,” declared Nixon’s successor, Gerald Ford, and it was. Nixon faded into jowly retirement. But Trump yearns to regain the crown. Woodward spoke to the Guardian by phone six hours before the disgraced one-term, twice-impeached president took the stage at Mar-a-Lago, his gaudy personal...