Well perhaps we are looking at it through a different lens:
The Republican Party, while it also attracted many anti-slavery Democrats, drew off so many Whigs that they effectively killed the Whig party
The Whig Party
So essentially becoming the republican party, perhaps not rubber stamped as you would like but, non the less most Whigs ended up in the republican party. It all depend how you look at it.
In regards to getting the name wrong it was a more or less a typo after a very long day. Although you got the idea, this isn't a college exam so if your going to nit pick at spelling a typo's you can _______off.