And for the record, John Frémont did come much much closer to winning the Presidency in 1856 than did a conservative in 2008.
You can talk about 2008 somewhere else. I am looking for Civil War buffs here.
I can answer the question on how well Frémont did. He carried 11 states for a total of 114 EVs (with 33% of the vote, far below McCain). Had Millard Fillmore gotten out of the race and endorsed the GOP ticket (he placed a respectable 3rd), Frémont would have actually won the national vote (with nearly 55% of the vote), but he still would have lost the electoral college, adding just CA, IL & NJ to his column (which would’ve been 152-136 in Buchanan’s favor). The 1856 race actually resembled (in actual vote breakdown) more like the 1992 Clinton-GHW Bush-Perot one.
Frémont more than likely would’ve faced the same problems as Buchanan and had he aggressively pursued abolitionism, probably would’ve sped up the onset of secession by 1857/1858, or the Democrat-majority Congress would’ve tried to impeach him. To Buchanan’s credit (with respect to a last ditch effort to save the Union), he at least (in 1860) cleared out his cabinet of all the Southern sympathizers, but too little too late. He was in a terrible bind having to hold together a fracturing Democrat majority, and in a no-win situation. I’m not nearly as hard on him as many other historians are.