How commonplace is it to name Naval vessels after living servicemen, politicians,etc.?
Used to be they named carriers after famous battels ( Lexington, Yorktown, Saratoga, Midway, ...Battleships after States...Iowa,New Jersey...Cruisers after Cities...Indianapolis...Submarines after fish...Tarpon,Skipjack... )
Uncommon, but it's been done before. CVN-70 (Carl Vinson) comes to mind. Vinson participated in the ship's christening but I think he passed away before the ship was commissioned. Ronald Reagan was around when they decided to name CVN-76 after him but passed away before the ship was built.
You have the USS J F Kennedy and the USS Reagan was commissioned while he was still living.
Lately? All too common.