<P> The Progressive Era (1896--1932) witnessed the rise of strong party leadership in both houses of Congress . In the House of Representatives, the office of Speaker became extremely powerful under Thomas Reed in 1890, reaching its zenith under the Republican Joseph Gurney Cannon . The Senate was controlled by a half dozen men, including Republicans Nelson Aldrich and Mark Hanna . A revolt against Speaker Cannon in 1910, led by George Norris, strengthened the seniority system and made long - serving Congressmen more independent of party . Committee chairmen remained particularly strong in both houses until the reforms of the 1970s . </P> <P> In 1901, President William McKinley was assassinated and his Vice-President, Theodore Roosevelt, succeeded him . As President, Roosevelt changed the Republicans image to be more progressive than pro-business . During his Presidency, which lasted between the years 1901 and 1909, Roosevelt became arguably the strongest leader of the entire Progressive Era . However, Roosevelt's successor, William Howard Taft, did not continue Roosevelt's progressive policies, and this resulted in a major break between the conservative (pro-Taft) and progressive (pro-Roosevelt) Republicans . In the 1910 midterm elections, gave the Democrats would regain control over the US House of Representatives once again, after the Panic of 1910--11 further shattered these uneasy relations between the conservative and progressive Republicans . </P> <P> There were two important structural changes to Congress around the turn of the 20th century: </P> <Ul> <Li> Direct election of senators . Senators were chosen not by state governments but by direct election, according to the Seventeenth Amendment . Author David Kyvig saw this as a positive development since "senators became much more sensitive to public opinion in their state", but advocates of states rights saw direct election of senators as undermining the authority of state governments within the national government and harming the principle of federalism . Congress has also been criticized for siding with the Supreme Court to undermine the ability of state governments to regulate their respective economies; critics see a pattern of interpreting congressional power "expansively" according to such cases as Wickard v. Filburn (1942) and Gonzales v. Raich (2005). However, in two cases, United States v. Lopez (1995) and United States v. Morrison (2000), the Supreme Court rejected arguments that the commerce clause allowed Congress to "regulate noneconomic activities merely because, through a chain of causal effects, they might have an economic impact ." The effect of the change to popular election of senators was to reduce the difference between the House and Senate in terms of their link to the electorate . </Li> </Ul>

When did congress become a full time job