NEW YORK — Leaders of Young Republican groups throughout the country worried what would happen if their Telegram chat ever got leaked, but they kept typing anyway. They referred to Black people as monkeys and “the watermelon people” and mused about putting their political opponents in gas chambers. They talked about raping their enemies and driving them to suicide and lauded Republicans who they believed support slavery.William Hendrix, the Kansas Young Republicans’ vice chair, used the words “n--ga” and “n--guh,” variations of a racial slur, more than a dozen times in the chat. Bobby Walker, the vice chair of the...