One and Done?

Fifteen first-term U.S. Senators are running for reelection this cycle (excluding Illinois Republican Mark Kirk who served a shade over a month in 2010 after winning special and general elections that November). Many of these incumbents are facing grim to uncertain prospects for winning a second term and history suggests at least one will be defeated. Across the 53 election cycles since the beginning of the direct election era in 1914, at least one first-term incumbent was defeated in 49 of them. First-term senators were only able to escape defeat during their renomination and general election bids in 1960, 1990, 2004, and 2010 with an average of 3.5 from this group falling short per cycle during this century-long span (188 overall). At least one U.S. Senator – tenure notwithstanding – has been defeated in every cycle during the direct election era.