Why was it possible that lincoln would not be reelected in 1864? apex?

In the year 1864, Lincoln had to face a new presidential election, an unprecedented situation considering that it would be carried out during a civil war.

In the presidential elections, held on November 8, 1864, Lincoln obtained 2 218 388 popular votes, which equaled 55.02% of the votes, while McClellan had managed to gather 1,812,807 votes, which represented 44.96% of the votes. the votes. In the Electoral School Lincoln had 212 electors against 21 of McClellan, since Lincoln had won in 23 of the states that participated in the election (the Confederates did not) and McClellan in only of them. Thus, Lincoln managed to be re-elected with an overwhelming majority; A significant element of this brilliant victory was that, by allowing many states that their citizens mobilized on the fronts could vote in theaters of operations of the war, Lincoln obtained 70% of the votes of the members of the Army.

On March 4, 1865, he began his second consecutive presidential term.

sorry i really dont know