David Damore (Political Science), Robert Lang (Lincy and Brookings Mountain West), and Karen Danielsen (Public Policy and Leadership) are the authors of "In 2020, the Largest Metro Areas Made the Difference for Democrats," which was published by The Brookings Institution Metropolitan Policy Program. The analysis applies the "blue metros, red states" framework to examine the 2020 presidential elections in the swing states and the 2021 Georgia U.S. Senate elections. By flipping Arizona and Georgia, President Biden won all swing states where a single metropolitan region represents 50 percent or more of a state's population. Since 2016 the Democrats have gained six seats in western and eastern Sun Belt states with metro regions of this scale. Las Vegas was one of four swing-state metro regions where Donald Trump improved his vote share.