With high-profile backing Carpenter ran successfully for the senate seat occupied by James R. Doolittle, a "Johnsonized" Republican who had fallen out of favor with his party. With his victory he solidified his status with the "Madison Regency," a Republican group that included former governor and Johnson's Postmaster General Alexander Randall, Madison postmaster Elisha W. Keyes and "Wisconsin State Journal" editor and Republican state central committee chairman Horace Rublee. After Rublee was appointed minister to Switzerland by President Grant, Keyes became party chairman and closely coordinated with Carpenter to distribute federal patronage jobs to political allies.