[okie01]

One might say that, had the Whigs the foresight to bunker up in New England, a rump might have survived into the 1880's...

[Publius]

It's unlikely the Whigs could have survived the Civil War, even by holing up in New England. The Whigs were never really a party, just a collection of disparate factions opposed to everything Andrew Jackson stood for and united behind Henry Clay as a figure of compromise.

Trivia question: The Republicans use the elephant as the mascot and the Democrats the donkey. What was the mascot of the Whigs?
Answer: A bulldog guarding a strongbox.

The Republicans stole the Whigs' thunder on the importance of commerce and were willing to take a stand on slavery. This was something the Whigs tried to dodge.

Before the 1850's the slavery issue could be discussed dispassionately by the Great Middle, even though discussion on the extremes always led to violence. By the time of the Kansas-Nebraska unpleasantness, and the unwillingness of the Pierce Administration to maintain law and order in the two territories, there was no longer any middle ground.

The Whigs bailed on the major issue of the day, and there was no way they could have survived the upheaval of the Civil War.