Voting is underway across the country Tuesday in a midterm election that could decide whether President Trump gets two more years of unified Republican rule — or faces a potential Democratic check on his power.Why it matters: The results will be the clearest national test of Trump's second presidency, following war abroad, economic anxiety at home and sweeping changes in Washington. Trump, facing all these challenges, has made himself the face of the Republican campaign for control.State of play: As voters head to the polls, the Trump administration is zeroing-in on the Alaska Senate race. The Department of Justice has sent more than a dozen target letters as part of its investigation into the Dan J. Sullivan campaign, which has been the subject of Trump's ire for several days.It's an escalation into the Trump administration's push for answers in the race where Democrats reportedly conducted an organized effort to recruit another "Dan Sullivan" to join Sen. Dan Sullivan (R) on the ballot.The Justice Department's move comes as the White House is circulating Election Day talking points across the administration, touting Trump's accomplishments as the GOP braces for a tough evening that could see them lose both the House and the...