Some historians argue that american political parties have been strictly practical coalitions, not ideological movements. yet the republican party came into existence primarily to oppose the extension

Some historians argue that american political parties have been strictly practical coalitions, not ideological movements. yet the republican party came into existence primarily to oppose the extension of slavery. what explains the rise of such an ideological single-issue party in the 1850s? why did the other single-issue party of the time—the anti-immigrant know-nothings—eventually fail, while the republicans not only survived but took power in 1860?