The thing about presidential indictment is that it's never been tested. I've seen rational arguments by legal beagles on both sides. I think (hope) that chances are something serious enough for indictment would be serious enough for impeachment & removal, which would remove that 'sitting president' obstacle.
Clinton's lying to a federal grand jury wasn't serious enough for removal because the reason for his lies was more of a 'moral' issue (concealing infidelity) than a 'criminal' one. Scrotus' crimes are more of a serious nature: conspiracy to direct the outcome of a federal election, fraud, and other financial crimes. Any lying he may do/have done in connection with his crimes will be a small piece of that huge pie.
IF we get to that point (impeachment) it will be interesting to see where the Senate falls on removal. Remember, we aren't just concealing an affair here, we are talking about crimes that, at any other time, would be considered treason.