The 1860 presidential election was a chaotic time. The Republican Party had 7 candidates at their convention and after 3 rounds of voting (and buying votes with promises of government contracts and cabinet positions) Lincoln was chosen. A man so weak he didn't qualify to appear on any southern ballot. The Democratic Party was in even worse shape, nominating Douglas who suffered Lincoln's same political weakness in the South. This prompted the Democrats to nominate a 2nd candidate, Breckinridge, to run in the South. Meanwhile, the Constitutional Union Party chose to fill the vacuum left by the Republicans who ran their own Southern candidate, Bell. This deeply partisan election was made even more chaotic by the geographic limitations of all 4 candidates resulting in 2 presidential elections ensuring that no matter who won, 1/2 the country would deem them illegitimate. This prompted Southern states to mobilize their militias both to deal with civil unrest caused by the election (with Kansas waging civil war) and in preparation for war with the North in as there was no escaping that 1 side would reject whoever became president. When Douglas toured the Southern states in an attempt to mend fences, his political irrelevance was made clear as angry mobs set upon him at every stop declaring him a traitor. When Lincoln 'won' the election with only 40% of the EC vote and none from the south, South Carolina declared independence and was quickly joined by most of the Southern states. Less than 2 months after being inaugurated, civil war broke out (with Kansas, Virginia and Alabama fighting their own civil wars concurrently). I bring this up because the 2016 presidential election mirrors the 1860 election. The Republican Party is in even worse shape than it was in 1860. The field once had 17 people and while most have dropped out, there is little hope of avoiding a convention. A convention vote would put these names back in play with several additional names being offered who didn't even run in the Primary. Both factions in the Party have made clear that the Party, like the Democrats in 1860, will have 2 candidates. If Trump wins, the Republican leadership will unite behind another, if he loses he'll run anyway (and incite his followers to violence). The Democratic Party is in no better shape. The Party leadership has pledged to run Blumberg if Sanders wins. Sanders for his part has pledged to back the nominee if he loses but this is of little consolation. Most of his followers have taken up the warning, "Bernie or bust'" meaning that even if he endorses Hillary, the party will still split with his supporters either staying home or writing him in (with a small but vocal minority warning they'd vote for Trump in protest). His pledge was made early, with 5 candidates running and polling in single digits so it doesn't take much imagination to see him running no matter the outcome at the convention (which he's pledged to go to no matter the delegate count). Even if he were to endorse Hillary in disregard for political reality, that would still leave it a deeply partisan 3 way race. Already politically motivated violence has broken out across the Republic and militias have already (however pathetically) challenged Federal authority in open battle. With sporadic violence, small but organized rebel militias, a candidate of means threatening a militant response to an unfavorable convention outcome, fascist and socialist revolutionary sentiment becoming mainstream politics and a Federal Government so illegitimate as to be outpolled by lice, the Republic again finds itself rushing headlong to it's self-destruction. Many have attempted to warn of the impending doom (most notably Trump and Cruz) but blinded and deafened by their passions, I fear the American people are oblivious to the threat they so gladly promote.
So what is the big threat? Trump supporters taking up arms against the country? I suppose it is possible but unlikely.
