Senatorial power had been a coefficient of Presidential weakness

Senatorial power had been a coefficient of Presidential weakness, and for thirty years, Presidents had either like Grant, or indecisive, or simply cowed by the mighty Senate. But with the crack of the assassin’s gunshot that struck down McKinley, and, to the rage of Senator Mark Hanna, put “that dammed cowboy” Theodore Roosevelt in the White House, the era of weak Presidents was over.

R. Caro, The years of Lyndon Johnson, Volume 3: master of the senate (2002), 37