After a tumultuous campaign and transition, President-elect Donald Trump will take the oath of office Friday as the least popular incoming president in at least four decades, but a majority of Americans nevertheless express optimism that he will be able to fulfill campaign pledges to boost the economy and deal with threats of terrorism, according to a Washington Post-ABC News poll. Amid controversy and calls for additional investigations into possible Russian interference in the election, most Americans disapprove of Trump’s response to the hacking and other activities.