The drumbeat of those seeking the resignation of U.S. Sen. Al Franken grew significantly on Wednesday. After a seventh accuser came forward — this time a former Democratic congressional aide — a growing list of U.S. senators called for him to step down, including many female lawmakers.

The Star Tribune Editorial Board now adds its voice to those asking Franken to step down immediately.

We expressed deep concerns about his ability to continue effective representation of this state even after the first accuser and the infamous groping photo. Now added to those concerns are more accusers and the defection of a string of important Democratic senators from Hawaii to New York. No senator can function effectively when he has lost the confidence of so many colleagues.

Franken is only partway through a second term and had only recently started to become a larger voice on the national stage, particularly with the publication of a new book. But the incidents of alleged sexual misconduct have become too damaging for him to continue. Franken has said he will make an announcement on Thursday: It should be that he is resigning.

If this is to be an actual turning point in our culture, there must be real and lasting consequences to behaviors that never should have been accepted. That these incidents came so late in Franken's life should make him all the more accountable. Instead, he has mostly offered hollow apologies that failed to acknowledge what happened.

Yes, Franken could redouble his efforts in the Senate. He has tried, in recent days, to reclaim his voice on important national issues. But it is, as we feared, drowned out by the loud and persistent string of accusations — from a fellow USO entertainer to autograph-seekers at the Minnesota State Fair to now a political aide of his own party who was in her mid-20s when she said Franken pursued her after her boss had left a recording of his radio show in 2006, and attempted to force a kiss on her.

Franken has been a powerful figure in Minnesota politics for well over a decade. He has contributed to Democratic causes, raised money, lent his presence and worked hard at his post. But the key consideration now and always must be who can best represent the people of Minnesota in the U.S. Senate, acting on their behalf as an effective voice in one of the world's most powerful bodies. There are other experienced, deserving figures in Minnesota who could advance Democratic values and positions, and without the baggage that now hampers Franken.

Some Franken supporters have said that so long as President Donald Trump, himself accused by a string of women of sexual misconduct, occupies the White House — and while Republicans continue to rally around Alabama Senate candidate Roy Moore, credibly accused of molesting and pursuing underage girls — Franken should stay. That is a cynical calculation that indulges in the same tribalism for which Republicans have been rightly criticized.

Democrats have an opportunity here to set a higher standard. They can give hope to women across the country that the old rules are, in fact, changing and that credible accusations won't be overlooked or hushed up but instead will trigger consequences.