Why did the know nothings fail?

The Know Nothing Party failed primarily due to internal divisions and a lack of a cohesive platform beyond their anti-immigrant and nativist sentiments. As the political landscape shifted, especially with the rise of the Republican Party and the looming issue of slavery, the Know Nothings struggled to maintain relevance. Additionally, their inability to address broader economic and social issues alienated potential supporters, leading to a decline in their influence by the late 1850s.