Election results from OpenElections.
Precinct shapefile from the Kansas Legislative Research Department.

Corrections to Johnson and Sedgwick Counties based on PDF map from counties. Some precincts split based on legislative district lines.

G12PREDOba - Barack Obama (Democratic Party)
G12PRERRom - Mitt Romney (Republican Party)
G12PRELJoh - Gary Johnson (Libertarian Party)
G12PREIBal - Chuck Baldwin (Reform Party)
G12PREOth - Other Candidates