We matched the list of frequent guests to ideological scores generated by Crowdpac, a website that makes detailed ideological comparisons between political candidates. They extend along a line from “10 Liberal” to “10 Conservative.” The analysis excludes former members of Congress who have contractual agreements to appear on one of the five shows: “Fox News Sunday,” NBC’s “Meet the Press,” CBS’s “Face the Nation,” ABC’s “This Week” and CNN’s “State of the Union.” The appearances were compiled from data collected by the Women in Politics Institute at American University.

When the Sunday shows have turned to former members of Congress, the same ideological pattern emerges: Conservatives have made 56 percent of the appearances, compared with 41 percent for liberals. As a group, the former conservative lawmakers were slightly more liberal than their current counterparts.

The ideological tilt relies on the frequency of appearances by conservatives; setting aside the number of times they are guests, the universe of lawmakers who are on Sunday shows is close to evenly split between conservatives and liberals. Neither current nor former lawmakers with the highest ideological Crowdpac scores have appeared on the Sunday programs, the data show. Lawmakers with scores of 7, 8 or 9 in either direction account for 36 percent of the House and Senate, but made one quarter of all congressional appearances on the shows.