The only people who are contented with a system of promotion by mere seniority are those who are contented with the triumph of mediocrity over excellence.
 Theodore Roosevelt, State of the Union Address. copy citation

Context

“The service thereby rendered not only to the Regular Army, but to the National Guard of the several States, will be so great as to repay many times over the relatively small expense. We should not rest satisfied with what has been done, however. The only people who are contented with a system of promotion by mere seniority are those who are contented with the triumph of mediocrity over excellence. On the other hand, a system which encouraged the exercise of social or political favoritism in promotions would be even worse. But it would surely be easy to devise a method of promotion from grade to grade in which the opinion of the higher officers of the service upon the candidates should be decisive upon the standing and promotion of the latter.” source