I think this a good vote from Donnelly's point of view. He isn't going to forget that the constituency/voting bloc that put him into power was voters who were uncomfortable with Murdock's comment on rape. Those voters, even if plenty of them are leaning Republican, will be comfortable with Donnelly's statement regarding sexual assault. They put partisanship aside and voted for a Democrat in the face of rape comments; that same Democrat then went on and said that we shouldn't confirm someone to the court who has sexual assault allegations against them.
So yeah, if anything this gives lean Republicans who voted for Donnelly a "I made the right choice" moment and gives them more comfort in voting for Donnelly a second time if they were considering drifting back into their natural Republican column.
Yeah, the same people that voted for DJT after Access Hollywood. Things have changed since 2012, and we need to accept the new reality.