Why did Abraham Lincoln lose the election of 1858?

He refused to publicly debate his opponent.

More citizens voted for his opponent.

Republicans won a majority in the Illinois legislature.

Democrats won a majority in the Illinois legislature.

On election day, the voters of Illinois chose members of the state legislature who in turn reelected Douglas to the Senate in January 1859.

But this situation only benefited Lincoln n the future because he gained a massive popularity in the north while Douglass election created a major divide of power in Democratic party. So, the answer is "B."

There was no election in 1858. Lincoln won the election of 1860.