The Independent senator from Maine said he doesn't know who President Trump will nominate, but the senator wants to do his research on whoever the nominee is.
President Trump is looking to fill the Supreme Court seat of retiring Justice Anthony Kennedy.
Senator King made these comments while at a meeting in Belfast on Friday.
He said he will attend the hearings on whoever the nominee is, even though he is not on the judiciary committee.
"This may be the most important vote I'll ever take because this is a 40-year job or at least a 30-year job. It's a life-time and there's no do-over," said Senator King. "So I'm going to try to make the best decision that I can, thinking long term how will this person affect the country going forward."
The senator said he doesn't believe a nominee who holds ideologies too far on either side of the aisle could get the needed votes.