In a video shared on Twitter, the 83-year-old Utah Republican announced his plan to leave the Senate early next year after more than 40 years. Hatch's announcement came just a little more than a week after the Republican tax plan that he helped to craft was signed into law.

President Donald Trump had urged Hatch, the Senate Finance Committee chairman, to seek re-election later this year. Hatch showered Trump with praise during and after Congress' passage of its tax bill, setting himself apart from some GOP senators who criticized the president's actions or fitness for office this year. 

In the video, Hatch said he was "deeply grateful" to serve as a senator and said "the next chapter in my public service is just beginning."