SCOTUS said you can - Paula Jones case. An idiotic decision, IMO.
They ruled that Clinton could be sued for actions before he was president, not actions while he was president and most importantly, not for actions AS president.
IIRC, SCOTUS said that the Jones’ case would not interfere with the POTUS’ duties.
***For the record, I voted for Clinton twice, and thought he should have resigned when Lewinsky came up.
That was for actions unrelated to his presidential duties. You can’t sue a president for acting as president.
SCOTUS proclaimed that the world at large could pursue a lawsuit against a president only after he left office.
The Jones suit pertained to an action that occurred BEFORE Slick became President. A standing President cannot be sued for actions taken while President.