Why was Abraham Lincoln compared to Benedict Arnold?

Elected as a Whig to Congress in 1846, Abraham Lincoln gained notoriety when he lashed out against the Mexican War, calling it immoral, proslavery, and a threat to the nation's republican values. President James K. Polk had called for war, accusing Mexico of shedding of "American blood on American soil.” Lincoln responded by introducing a series of resolutions demanding to know the "particular spot of soil on which the blood of our citizens was so shed." One of Lincoln's constituents branded him "the Benedict Arnold of our district," and he was denied renomination by his own party.

Explanation:

it's no easy i swear it's hard

regarding the law, the 15th amendment was specifically designed thinking in the rights of black free men.

even though ratified on february 3, 1870, the promise of the 15th amendment would not be fully applied for a long time.poll taxes and literacy tests would allow southern states disenfranchise african americans. only in 1965 the voting rights for african americans would be actually able to vote in the south.

in 1965, president johnson signed the voting rights act, which aimed to overcome legal barriers that prevented african americans from voting as it was guaranteed by the 15th amendment to the u.s. constitution.