"The Second Party System, in fact, was near death before January 1854, when the Nebraska bill was introduced, because the dynamics of interparty conflict that sustained it had already been largely eroded. The two-party system collapsed because Whig and Democratic voters lost faith in their old parties as adequate vehicles for effective political action, and they lost faith because social, economic, and political developments between 1848 and 1853 blurred the line that divided Whigs from Democrats on a host of issues. ... Once agreement, or seeming consensus, on issues had replaced conflict between the parties at the national, state, and local levels, therefore, the ties that bound voters to their old parties frayed and often completely snapped. The result of their disillusionment in 1852 and 1853 was apathy, abstention, and alienation." (102-3)
"What united the men who passively abstained in 1853 with those who actively bolted to new parties was a mounting antagonism to politicians and the mechanisms of the old parties, like conventions, which enhanced their control over the rank and file." (133)
"Once faith in those parties collapsed, however, a sense of crisis developed that government was beyond control of the people, that it had become a threatening power dominated by some gigantic conspiracy, and hence that republican institutions were under attack. Politicians in the North and South responded to this sense of crisis by making an enemy in the other section the chief menace to republicanism who would enslave the residents of their own section." (258-9)