In the 1860's, the Supreme Court was a 'partisan creature' and President Lincoln and the Republican Party remade it so that it reflected the party's priorities.
Lincoln's chances of reelection in 1864 were dim. He was presiding over a bloody civil war, and the public was losing confidence in him. But he steadfastly rejected pleas to postpone the election.
When fighting a lethal foe on home soil, Lincoln expertly managed leading politicians; related well with the people; and dealt clearly with the military.
In 1868, during the impeachment trial of President Andrew Johnson, the Senate tied on two votes. Chief Justice Salmon P. Chase broke both ties.