In the world of finance, the adage “past performance is not indicative of future results” serves as a warning for investors. But in politics, past performance can provide a handy measure to assess the vulnerability of members of Congress, especially early in an election cycle.
And 18 months from the 2026 midterms, the first half of our list of the 10 most vulnerable House incumbents is dominated by battleground district members who each won their seats last fall by a percentage point or less. Freshmen are also heavily represented in the Top Five.
The incumbents who occupy the second half of our list are more seasoned and had slightly more comfortable margins of victory last year – with the exception of Rep. Jared Golden. The Maine Democrat secured a fourth term by less than a point in a district that President Donald Trump carried by 9 points. But Golden, along with Nebraska Republican Don Bacon, New York Republican Mike Lawler and Washington Democrat Marie Gluesenkamp Pérez, have repeatedly won reelection through the strength of their unique brands, which has helped them overcome the unfriendly political headwinds in their districts.
