If confirmed by the Senate, the 53-year-old conservative judge, who is well known in Washington legal circles, could serve for decades and have a major say over environmental regulations issued by future presidents, long after Trump has left office.
Some conservatives have expressed concerns about Kavanaugh - a longtime judge and a former clerk for Kennedy - questioning his commitment to social issues like abortion and noting his time serving under President George W. Bush as evidence he is a more establishment choice.
Senate Majority Leader Mitch McConnell has said the Senate will vote on the court nominee in the fall. "A judge must interpret statutes as written and a judge must interpret the constitution as written", Kavanaugh said in a ceremony, highlighting his family, Roman Catholic faith and distinguished legal career.
"It is my honor and privilege to announce that I will nominate Judge Brett Kavanaugh to the United States Supreme Court". Kavanaugh's nomination "sets in motion a hard right turn for the country that may be irreversible in our lifetime", said Nan Aron, the president of Alliance for Justice, a liberal group that has studied Kavanaugh's judicial opinions. CNN reported no Democrat lawmakers were in the East Room when Trump made his announcement.
On the other side, Republicans will pressure Democrats in Trump-supporting states and who are in electoral contests during the mid-term elections to break from the party and vote for confirmation.
But conservatives perceive Kavanaugh's time as a Republican operative favorably, and his connections from years in the executive branch could serve to soothe Republicans ahead of what could very well be a confirmation fight.
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He previously worked in the Bush White House as Assistant to the President and Staff Secretary and was a partner at the Kirkland & Ellis law firm. "No single prosecutor, judge, or jury should be able to accomplish what the Constitution assigns to the Congress".
Judge Kavanaugh is a graduate of Yale College and Yale Law School and has excellent conservative credentials.
Republicans hold a mere 50-49 Senate majority, with the prolonged absence of the ailing Arizona GOP Sen.
The Judicial Crisis Network announced its "Confirm Kavanaugh" campaign of cable and digital ads in Alabama, Indiana, North Dakota and West Virginia.
Kavanaugh denied any involvement in crafting legal policy allowing for harsh interrogation tactics during the Senate's consideration of his nomination to the D.C. Circuit in 2005 and 2006. Susan Collins of ME and Lisa Murkowski of Alaska, who have shown concern in the past about preserving access to abortion rights.
The White House would love to have the Democrats' votes for confirmation. Marjorie Dannenfelser, the president of the conservative Susan B. Anthony List, told reporters on a press call that the nomination of a fifth conservative justice is the culmination of years of work getting Republicans elected to all branches of government.
"Make no mistake about it, Justice Kennedy himself was quite conservative".
"My introduction to the law came at our dinner table when she practiced her closing arguments", Kavanaugh said.
Anti-abortion-rights activists do not disagree.