According to state election law, the governor would call for a special election to fill the seat. There would almost certainly be primaries, too, given the timing of Watt's nomination.
The Democratic field could grow crowded, too. The Charlotte Observer reported that an election could be held before the scheduled city elections this fall depending on when and if Watt departs.
The Observer also mentioned state Sen. Malcolm Graham and state Rep. Alma Adams as locks to run for Watt's seat if he is confirmed. State Rep. Marcus Brandon is another name the paper mentioned.
There is skepticism about Watt on both ends of the political spectrum, so until he is confirmed, it's not a sure bet that his seat will be vacant.