United States Senators face reelection every six years, and members of the U.S. House of Representatives have to be voted back into office every two years. As a result — though not a part of the official job description — remaining popular is critical for members of Congress. 

Unlike U.S. presidents and most state governors, congressional representatives do not have term limits. As a result, they can keep their jobs as long as they remain popular and in good health. Some representatives on Capitol Hill are better at that aspect of the job than others. Throughout history, dozens of senators have served for multiple decades. Here is a look at the longest serving Democrats and the longest serving Republicans in the house. 

24/7 Wall St. reviewed approval ratings for U.S. Senators and 2018 election results for House members in order to identify the least popular members of Congress. Data on senator approval ratings came from data research company Morning Consult, and margins of victory in the midterm elections came from Ballotpedia, an online encyclopedia of American politics and elections. 

In politics, it is nearly impossible to serve everyone’s best interest at all times. And partially as a result, approval ratings for the senators on this list do not exceed 65%. In a few cases, the most popular senator in a given state even has an approval rating under 40%. 

For members of the House, popularity, as measured by margin of victory in the ballot box, can be far higher. This is partially because house members typically have a much smaller — and sometimes more like minded — constituency to appeal to. Here is a look at America’s largest and smallest voting districts. 

Click here to see the most popular members of Congress from every state.
Click here to see the least popular members of Congress from every state.
Click here to see our methodology.