The Jacobite's weren't happy with the 1707 act of union, and wanted their stewards back, but were defeated in the fifteen. My textbook says that this lead to the Tories being purged from public offices, and helped with the Whig Ascendancy, but its unclear why. Didn't the Tories love the monarchy?
Tories were seen as partial to the centralised absolutism of France while the Whigs were strong supporters of the enlightenment-influenced constitutional monarchy that'd been formalised after William and Mary of Orange deposed King James II and VII in the so-called Glorious Revolution. In addition to that, among the Tories were many who were either openly or suspected Roman Catholics and/or supporters of the legitimacy of the Stuart claim to the throne. For those reasons Toryism in the late 17th and early-mid 18th centuries was associated with Catholicism and disloyalty. Those associations coupled with the Jacobite Rising gave Whigs and their supporters ample justification to purge Tories from power to secure their own ascendancy.
Source:
Brewer, John. The sinews of power: war, money and the English state, 1688-1783. London: Routledge, 2014. Print.