Robert who was the longest-serving senator in US history, at 51 years

Let's find possible answers to "Robert who was the longest-serving senator in US history, at 51 years" crossword clue. First of all, we will look for a few extra hints for this entry: Robert who was the longest-serving senator in US history, at 51 years. Finally, we will solve this crossword puzzle clue and get the correct word. We have 1 possible solution for this clue in our database.