Gerry Adams is not a stupid man, whatever his Twitter account may show. He knows he is an electoral liability to Sinn Fein in the Republic. So, something else must be going on for him to remain leader into the next election and beyond (as predicted here that he would some time ago).
The answer is the potential for a Sinn Fein ubiquitous split North and South were Adams to go now. There is always talk of republican splits, of course. But Adams remains the only figure with a cult-like status who can maintain an iron-fist authority over the party, North and South.
What does all of this mean for Mary Lou McDonald, who has served her time defending the indefensible - kangaroo courts-related torture, murder, rape and the like, which at a human level must surely make her womanly skin crawl? In my view, Adams's decision to remain increases the likelihood that she will not be the next, and therefore never be, president of Sinn Fein.