One who engages in schadenfuckery, which is the act of facilitating another's misfortune for one's own pleasure.
Related to schadenfreude, but different. Schadenfreude only involves feeling pleasure from another's misfortune. A schadenfucker actively (or through inaction) helps cause or worsen another's misfortune, for their own pleasure.
One schadenfucker decided not to support Hurricane Harvey relief efforts because Texas voted for Trump in the 2016 presidential election.