In short and simple terms, the phrase "to hold the seat" means to remain in a position of power or authority, typically in a political or organizational role. It refers to maintaining control and staying in the same position.
Sentences with «to hold the seat»
Instead of seat belts, special anchors hold the seat in place. (acog.org)
The side handles allow your child to hold the seat for a safer and more confident training session. (checkpregnancy.com)
That basically gave the interested candidates 8 days to run one of the shortest campaigns in recent memory to succeed Silver who held the seat since 1977. (nystateofpolitics.com)