For President Trump, the new year comes with seemingly endless possibilities. A Senate conviction and removal from office, a landslide defeat at the ballot box, reelection by a larger margin than his improbable 2016 victory — all of these options are on the table in 2020. The president is, as walking malapropism machine Little Carmine Lupertazzi tells Tony Soprano, “at the precipice of an enormous crossroad.” “Expect the unexpected,” said John Feehery, a Republican strategist. “This guy plays by his own, completely unconventional playbook.” This has members of Trump’s party both cautiously optimistic and worried that unforced errors could allow the Democrats to finish what they started in the midterm elections. Trump is a thoroughly unconventional politician thrust into an unusual set of circumstances. No president ever faced the prospect of impeachment at the same time he was getting ready to face the voters. The year could begin with a Senate trial and end with him winning a second term. Or, even if Trump is not removed from office, the whole process could, as leading Democrats undoubtedly hope, leave him mortally wounded in his quest for reelection. “The fourth year of Trump’s presidency seems likely to resemble the first three, which is to say every day is unpredictable,” said Alex Conant, a Republican strategist and former communications adviser to Sen. Marco Rubio. “How Trump handles his Senate trial could set the tone for the year.”...