In the political vacuum created by this alienation, the Southern wing of the Whig Party was formed. The party was a coalition of interests united by the common thread of opposition to Jackson, and more specifically to his "definition of federal and executive power." The party included former National Republicans with an "urban, commercial, and nationalist outlook", as well as former nullifiers. Emphasizing that "they were more southern than the Democrats," the party grew within the South by going "after the abolition issue with unabashed vigor and glee." With both parties arguing who could best defend Southern institutions, the nuances of the differences between free soil and abolitionism, which became an issue in the late 1840s with the Mexican War and territorial expansion, never became part of the political dialogue. This failure increased the slavery issue's volatility.