In an announcement video released on Feb. 12, former astronaut and Navy pilot Mark Kelly announced that he would run for an Arizona U.S. Senate Seat.

Just 12 hours after he posted it, Kelly’s announcement video on his Twitter account had well over 2 million views.

Since his wife, former U.S. Representative Gabby Giffords was shot in an assassination attempt, he has fought for stricter gun control. Kelly mentions in his video that he learned how public policy can have a transformative effect on the lives of others from Giffords time in office. This is one of the reasons why he is launching his 2020 Senate campaign.

This upcoming election will decide who will fill the seat of Senator John McCain for the final two years of his Senate term, after he passed away last August. Whoever wins this seat would have to run again in the 2022 election. Currently, Republican Martha McSally is filling this seat in the U.S. Senate. She was appointed to the seat by Gov. Doug Ducey after McSally lost former Senator Jeff Flake’s seat to Democrat Kyrsten Sinema.

Kelly is the first person to announce that he is running for this Senate seat. However, Democratic U.S. Representative Ruben Gallego is thinking about running for the same seat, which would mean the two would have to compete for the nomination. Just last week, former state Attorney General Grant Woods announced that he had no plans to run for the Democratic nomination for this Senate race.