The man is now an embarrassment – and the sooner he hands over to a successor less tainted by IRA violence, the happier many in his party will be.
Adams' arrest on Wednesday night could not have come at a more awkward time. Just as Sinn Fein was trying to project a fresh new image for the upcoming elections, its boss was taken into police custody and questioned about an horrific 42-year-old murder.
The ghost of Jean McConville clearly cannot rest easy, and it continues to cast a long shadow over the man who has been accused by former colleagues of ordered her kidnapping and execution. He denies involvement.
Adams has been interrogated by British security forces before, so this particular experience has probably not rattled him too much.
The same cannot be said for his deputy and likely successor, Mary Lou McDonald.
The Dublin Central TD sounded deeply uncomfortable at a press conference yesterday, resorting to feeble conspiracy theories about Gerry's arrest being masterminded by old-style unionists.
Mary Lou also went off-script when she admitted that the death of Jean McConville could be described as "murder".
Until now, Sinn Fein looked certain to be the big winners in this month's local and European elections. Opinion polls show that that they could elect an MEP in all three constituencies and double or even triple their number of councillors.
The last thing they needed this week was a stark reminder that Sinn Fein once had a military wing and that group included a widowed mother-of-ten among its victims.
Of course, the arrest of Gerry Adams may not hurt Sinn Fein's election chances as much as its opponents hope.
The sad reality is that many people already know about the Shinners' bloody legacy and are either not bothered – or actually approve of it.
Even so, losing just a few floating voters because of this week's controversy could make all the difference between a good result and a spectacular one. So will Mary Lou take Gerry aside and politely suggest that after 31 years he might like to spend more time with the teddy bear he is always tweeting about?
This would not be easy, since Sinn Fein is more of a nationalist cult than a normal political party. Adams rules it like a tribal chief and is regarded by some veteran comrades as Belfast's answer to Nelson Mandela.
There is also the problem of Gerry's enormous ego. Even at the age of 65, he has apparently set his heart on leading Sinn Fein into yet another general election.
In his wildest dreams, he may even hope to become Taoiseach or Tanaiste just in time for the centenary celebrations of Easter 1916.
Sinn Fein's young bloods cannot afford to indulge these fantasies any longer. The party may seem to be on a roll these days, but it will not be fit for government in the Republic until Adams and his contemporaries are forced to leave the stage.
To put it bluntly, there are too many skeletons in his closet – and too many allegations about his IRA links that he has simply not been able to explain away.
In a recent TV3 documentary, Mary Lou McDonald confirmed her leadership ambitions – while buying a box of Cheerios in the local supermarket.
It is now time for Mary Lou to say "Cheerio, Gerry".