sentences:  Chase surreptitiously sought the 1864 Republican nomination, and he frequently worked to undermine Lincoln's re-election, but Lincoln nonetheless retained Chase due to Chase's competence as Secretary of the Treasury and popularity among Radical Republicans.Chase offered his resignation in June 1864 due to a dispute over an appointment, and Lincoln, having just been renominated for president, accepted Chase's resignation.Lincoln replaced Chase with William P. Fessenden, a Radical Republican who had served as Chairman of the Senate Finance Committee.