Little recent history:

A 50-50 Senate is not a stable thing. Yes, Dems would have the advantage since Harris would break ties. But so did the GOP after the 2000 elections...

In January 2001, the Senate was 50-50, and Dick Cheney was VP, so the GOP would win any tied votes. This only lasted until May, when Jim Jeffords of Vermont left the GOP and became an independent who caucused with Democrats.

The move makes sense. The most moderate member of the VP's party doesn't want to be hounded before every vote with all eyes on him doing something that will be unpopular in his home state. In 2001, the most moderate member of the VP's party was Jeffords. Today, it's Joe Manchin.

In the past, Joe Manchin could vote against his party when it would look good in WV because his vote didn't really matter most of the time. He could vote yea on Gorsuch, for example, because the GOP already had 51 votes for Gorsuch, so he was going to be confirmed anyway.

In a 50-50 Senate, Joe Manchin's vote would matter every time the GOP is able to get its caucus to fall in line. And if Democrats try any aggressive left-wing policy, you better believe McConnell is going to get them all to fall in line.

If we get a 50-50 Senate after tonight, GOP leadership is going to be talking to Manchin about caucusing with them. Easy to see how that conversation would go, "Look, Joe, you're in one of the reddest states in the country, your governor switched parties already,

"the other senator from your state is a Republican, and you're the only Dem elected statewide. You don't want Schumer hounding you for every vote, and you're not a far-left guy. Caucus with us, and we can provide a check and prevent anything radical from happening."

Harry Reid was able to convince Jim Jeffords to switch parties in 2001. Could the GOP convince Joe Manchin in 2021? If we get a 50-50 Senate, we will have to wait and see.