Chuck Schumer and Hakeem Jeffries are both cautious, calm, compromise-minded leaders fantasizing about a serious, sensible Democratic-run Congress.But social media is a temptress no party leader has tamed. The seduction of attention, likes and followers invariably proves too strong for the savviest, most self-promotional politicians to resist.Why it matters: That's the lesson of the Internet Era of American Politics — the algorithms always win.