With the news that Democratic congressmen Henry Waxman and George Miller plan to retire at the end of the year, Michael Barone looks back at the impact their congressional class of 1974 has had on American politics.

… [T]he Class of 1974 is about to pass into history. What did it accomplish?

First, it changed the way the House of Representatives operates, starting from before its members took the oath of office and continuing to the present day.

Democrats had held majorities in the House for 20 years, but the liberal majority in the caucus was often stymied by the seniority system that allowed conservative Southerners to hold key chairmanships.

Beginning in 1974, the leadership allowed the Democratic caucus to vote up or down on chairmen against whom a certain number of signatures were gathered.

San Francisco’s Phil Burton, who had shrewdly backed many ’74ers, gathered a sufficient number of signatures for every chairman. Three were defeated by the newly enlarged caucus, including one, first elected in 1940, who addressed the freshmen as “boys and girls.”

Election of committee chairmen became routine, and it meant that anyone seeking a chair had better have a voting record in line with the Democrats’ liberal majority. For example, Jamie Whitten of Mississippi, first elected a month before Pearl Harbor, shifted suddenly from right to left.

Republicans did something similar when they won their House majority in 1994. Their 73 freshmen, shrewdly backed and mentored by Newt Gingrich, supported his move to have chairmen chosen by a leadership-dominated steering committee.

The result is that the Democratic Caucus became solidly liberal and the Republican Conference (the two parties use different names) solidly conservative. The polarized House is in large part the product of the Classes of 1974 and 1994.

The change can be justified on neutral principles. Committees more closely resemble the legislature as a whole, which makes legislating more feasible — and party leaders and members accountable to the voters.

The downside, in some critics’ view, is that the election of chairmen also gave would-be chairmen motives to raise money for other members, very often from K Street lobbyists.