It's smooth sailing for Sanders and Leahy

Not that the current congressional delegation is in any serious risk of being defeated any time soon, but just how powerful is the advantage of incumbency? In Vermont -- very.

The last time an incumbent U.S. Representative from Vermont lost an election to a challenger was in 1990 when Peter Smith (R) was defeated by Bernie Sanders (I-Burlington).

On the other hand, since the state held its first direct election for U.S. Senator in 1914, no incumbent who ran for re-election has been defeated by a challenger.

We would have to go back to the era before direct elections to find an example of an incumbent senator losing re-election. That distinction goes to Nathaniel Chipman, a Federalist who served only one term from 1797 until 1803