Given the task definition and input, reply with output. In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].

(CNN) Black voters should not be blamed for Hillary Clinton's stunning election night loss of the presidency. The roots of Donald Trump's shocking, long-shot, and divisively improbable rise to the presidency can be traced back to election night four years ago when black voter percentage, for the first time in American history, surpassed whites. Black voters led the multiracial groups of voters that re-elected Barack Obama and seemed poised to do so in future presidential election cycles. But a strange thing happened on the way to a rendezvous with victory. The Supreme Court's 2013 Shelby v. Holder decision did more than just effectively gut law enforcement provisions of the Voting Rights Act. More profoundly, it neutralized black voter participation in key electoral battleground states, including North Carolina and Florida -- states that provided president-elect Trump's margins of victory.Peniel Joseph: Trump's victory isn't the fault of black votersSince 2012, voting rights for African Americans have been under attack 
 Question:During the 19th century and earlier, enslaved _ were denied the vote and punished, even killed for openly expressing dreams of black citizenship.

American