Every two years, one inevitable question on the minds of pols and members of the media is whether the minority party will be able to take control of its congressional chamber in the coming election. The answer often is no — at least, since the Civil War era. Although partisan turnover does happen, such in as the wave election that led to the GOP takeover of the House in 2010, years have often passed with the same party holding control.
Even with the best polling, no one can predict with absolute certainty what the outcome of any election will be. But data can show us what has happened. Below is a graph illustrating the partisan control of the House on the first day of each Congress since the first one, according to data from the House of Representative's Clerk Office.
The vertical axis represents the percentage control of the House each party enjoyed; the horizontal axis is the number of the Congress. For details, hover the cursor over each line; to highlight a party, click on that party in the legend. Party designations are those of the House Clerk's Office.
Are the first 34 congresses hard to read? Parties ranging from the Anti-Jacksons to the Adams supporters came into existance before largely disappearing as ideological positions shifted. Below is a close-up of those first congresses.