Sen. Al Franken (D-Minn.). (Melina Mara/The Washington Post)

SEN. AL FRANKEN (D-Minn.) declared Thursday that he will be resigning from the Senate, making him the second lawmaker, after Rep. John Conyers Jr. (D-Mich.), to depart Congress amidst its reckoning with sexual harassment and assault. Announcing his resignation, Mr. Franken said he was "hopeful" that the national conversation on harassment "would result in real change that made life better for women all across the country." His departure is itself a welcome sign of that change.

When a radio host accused Mr. Franken of kissing her without her consent and groping her while she slept, the senator promised cooperation with an investigation by the Senate Ethics Committee. That was three weeks ago. Since then, seven other women have come forward, three by name, with allegations. Several describe Mr. Franken touching them inappropriately during photo opportunities — in at least two cases, after his 2008 election to the Senate. Most recently, a former Democratic staffer, who did not give her name, described Mr. Franken attempting to forcibly kiss her after the taping of a radio show in 2006. "It's my right as an entertainer," Mr. Franken reportedly said.

These allegations have not been proved beyond a reasonable doubt. But the doubts Mr. Franken faced were over the appropriateness of his continued service as an elected official, not his criminal guilt. Though he disputes many of these women’s stories, there is more and more credible evidence of his apparent pattern of harassment. As with the departure of Mr. Conyers, Mr. Franken’s choice to leave Congress sends an important message that even powerful men can be held accountable for their misconduct. It’s disappointing that the senator, who appears to recognize the power of this cultural moment, chose to dwell on his accomplishments during his resignation speech rather than apologize.

Mr. Franken himself noted the contrast between his own resignation and Republican support for both President Trump — who stands accused of sexual harassment by at least 13 women — and Alabama U.S. Senate candidate Roy Moore — who allegedly preyed on girls as young as 14. There was a degree of political calculation in Senate Democrats' push Wednesday for Mr. Franken's resignation. His departure allows Democrats to more easily pillory Republicans for hypocrisy on sexual harassment as the Alabama election draws near — charges to which the GOP has left itself sadly vulnerable.

There’s a vast difference between an unwanted touch and child molestation; Mr. Franken’s alleged behavior is far less egregious than that described by Mr. Moore’s all-too-credible accusers. But it should not be hard for men to understand that conduct of the sort described by Mr. Franken’s accusers also is unacceptable. For too long, Congress has positioned itself among those institutions that countenance misconduct toward women. Congressional leadership must make clear that no level of sexual harassment will be tolerated.