All nine U.S. House districts in Tennessee now lean Republican, according to the latest Partisan Voter Index data from the Cook Political Report, which measures how strongly a district tilts toward one party compared to the national average.
The districts range from R+9 to R+29—meaning even in Tennessee's closest Republican seat, GOP candidates typically outperform the national Republican vote by nine percentage points. The strongest district, at R+29, ranks among the most reliably Republican congressional seats in the country.
The PVI is calculated by averaging a district's Democratic and Republican presidential vote shares over the previous two election cycles and comparing those averages to the national result. An R+10 district, for example, means Republican presidential candidates have outperformed their national average by 10 percentage points in that area over the last two cycles.
The across-the-board Republican advantage presents a steep climb for Tennessee Democrats. Any Democratic candidate would need to overcome substantial partisan headwinds to win statewide.
The strength of these numbers means primary elections function as the de facto general elections in most districts. The real competition occurs among Republican candidates competing for the party's nomination, not between Republicans and Democrats in November.
