Yes they can, but that creates a vacancy (which the Governor fills) rather than allows the Democrat to take office.

Reportedly, she's considering delaying the election so the Party can make an effort to get Moore to drop out.

I should not have assumed their governor would be another extreme right winger

Being elected is not enough. The senate has to vote him in. Usually it is just a formality. However, they could indeed not seat him.

This has happened before in both houses of congress:

https://en.wikipedia.org/wiki/Unseated_members_of_the_United_States_Congress

Interesting stuff.

Congress can expel one of their own members, so even if there was some sort of requirement to seat him, they could then expel him.

We welcome Judge Moore to our Republican caucus"

Trump: "Judge Moore is a great man. He has great character. Alabama will be very, very proud of him"

Just watch

Hopefully in 2018 the voters strike back.

Sigh

Each House may determine the Rules of its Proceedings, punish its Members for disorderly Behavior, and, with the Concurrence of two-thirds, expel a Member.

They need his vote for tax cuts. There is no morality in the rethug party. Only greed and hate.

So if they confirm him, the Repukes are allowing a pedophile to serve as a United States Senator. Just saying.