Much like Captain America and Thor, Dick Lugar, the Republican Senator from Indiana, seemed invincible.
He's been serving in the Senate, largely uncontested, since 1976. And he is one of the oldest members.
But, recent polls have Lugar ten percentage points behind newcomer Richard Mourdock before the Republican primary tomorrow.
For more on the race, we turned to Margaret Ferguson.
Margaret Ferguson is an associate professor of politics at Indiana University-Purdue University.