1) stevep, have you noticed that no one (besides me, that is) has considered the politics of British Intervention being put to good use by the Union? Namely, if it can be spun as Britain trying to sabotage the Union war effort (even if not to destroy it outright), then once peace is established between the USA and UK the war effort can be doubled against the South? If anyone could pull off such a feat of political legerdemain, it would be Abraham Lincoln.
The Union basically fought the South with one hand tied behind it's back. But if the war becomes not just for the Union, but national survival, and revenge against the South for betraying the country to America's Original Enemy!?


Remember, steve, this is the 1860s, not the 1940s.
OTL, the South engaged 90% of it's available military manpower (minus minor militia and slave patrollers) for the duration of the war. The North, only 50%, and many of those were short-termers, anywhere from 3 year enlistments all the way down to 90 day militia. If the North should be struck by a Spanish-American War level of jingoistic patriotism following Britain's intervention and later departure, it'll be the South, not Britain, who faces the full wrath of the Union Army. Imagine a Union Army of in-for-the-duration enlistees and draftees matching close to the South's per capita level of mobilization?
Union curbstomp of the South. Consider these possible outcomes:
a) The war might be over by 1864 Election Day. Lincoln wins every state but his opponent's.
b) The war might be at a point comparable to OTL on Election Day. Lincoln wins in a landslide, slightly bigger than OTL's.
c) The war might be further behind than OTL on Election Day, but the country blames Southern Treason and Perfidious Albion for the level of the Union's progress up to that point. Lincoln wins, with a margin less than OTL's.
d) The war may be struggling even further back, but the rage in the Union is such that though Lincoln may be defeated, a War Democrat (it is unlikely to be McClellan ITTL, as his campaigns would have been butterflied) is elected, resulting in no stinting in the war effort. The front bursts in 1865, CSA runs out of food and warm bodies by the end of the Winter of 1865/66, the Confederacy is overrun before the 1866 off-year congressional elections. Big pickups for the Republicans that year, and in 1868 Grant is elected President.
2) The trick to remember is that the USA is NOT a parliamentary system. If it were, the "Lincoln Government" would probably collapse due to a vote of no confidence over the Trent Affair, and be replaced by the likes of Thaddeus Stevens (or Seward, if Lincoln had his way). America's cyclical elections mean that Lincoln still has until Inauguration Day 1865 to win the war, regardless of re-election. Also, the Democrats are prostrate, being the "Party of Treason". The Democrats in the North are split badly between the Copperheads (CSA sympathizers, many of whom were being bounced in and out of jail, those who weren't being put on a horse and sent South

), and the War Democrats (many of whom were determined to outdo the Republicans in their support of the war).