The patronage system, justified by Andrew Jackson as a way to promote democratic accountability over public administration, eventually concentrated power in the United States Senate.
By politicizing and inviting legislative meddling in a core executive function, patronage undermined the power of the presidency.
Patronage was a hassle for Jacksonian presidents such as James K. Polk, but after the Civil War, it facilitated the development of massive political machines helmed by senators.
Ultimately, the system collapsed only because of the assassination of James A. Garfield, leading to the passage of the Pendleton Civil Service Act in 1883, although the party machines and senatorial domination endured.