James Buchanan, our first gay president, holds a narrow lead only because BO hasn’t started a Civil War. Yet.
Buchanan didn’t start a civil war, to be fair.
He also did little or nothing to try to head it off, but then there wasn’t really anything significant he could have done that wouldn’t have actually precipitated the war a bit early.
It is just, barely, possibly that had a strong leader been elected in 1856 the country wouldn’t have gotten to where it was in 1860, at which point there was nothing anybody could do to prevent secession and war.
But I doubt any president would have made any real difference. Both sides viewed themselves, quite honestly, as only defending themselves against vicious aggression by the other side. How any president was supposed to bring an and to that spiral of suspicion and anger is beyond me.