Don’t scoff too much at this notable non-defection from a vulnerable red-state Democrat. Indiana Democrat Joe Donnelly crossed the aisle to vote for Neil Gorsuch in February 2017, one of only three Democrats to do so. Senate Republicans had to hope that they could convince him to do it again and make Brett Kavanaugh’s confirmation as bipartisan as it could get under the circumstances. Despite facing a tough challenge in the fairly Republican (and Trump-friendly) home state of Vice President Mike Pence, Donnelly has decided to demur:

Read Joe's statement on the Kavanaugh nomination: pic.twitter.com/JvjTOKEDyF

— Archive: Senator Joe Donnelly (@SenDonnelly) September 28, 2018

His opponent, Mike Braun, wasted no time in highlighting this as a campaign issue:

“This entire process has been an embarrassment to our democracy as Hoosiers watched firsthand how Senator Donnelly’s liberal colleagues used uncorroborated allegations to create a media circus designed to smear and destroy Judge Kavanaugh’s reputation. Donnelly’s decision to oppose President Trump’s highly qualified nominee is a grave mistake, but proves he is more concerned with standing with his liberal Democrat leaders than standing for Hoosiers. I continue to strongly support Judge Kavanaugh’s confirmation to the Supreme Court.”

Donnelly is already skating on thin ice in Indiana. The RealClearPolitics aggregation for Indiana only has four polls listed since Kavanaugh’s appointment, and Donnelly’s lead has steadily decreased over that period of time. The most recent poll from Fox News has Braun slightly ahead by two points (45/43), and that was taken largely before the allegations against Kavanaugh had emerged. Trump won this state by 19 points in 2016, don’t forget. RCP offered this analysis two weeks ago:

This is another race where Democrats looked to be in solid position over the summer, but where that position has deteriorated. Joe Donnelly still leads, but it is largely on the back of a month-old poll from Trafalgar Group. The Brett Kavanaugh nomination is something of a gut check for Donnelly, who needs to keep some Republicans in his corner without depressing the hyper-activated Democratic base.

This … isn’t going to help keep Republicans in his corner. In fact, it might generate more enthusiasm among GOP voters, whose enthusiasm has already begun to spike upward over the last couple of weeks. For an incumbent scoring in the low 40s, that is not a good development. However, it underscores how boxed in Donnelly feels on Kavanaugh with the Democratic base, which might end up costing the party a key seat that they need to get control of the confirmation process in the next two years.

Jon Tester’s also a no, but that was not a surprise, as CNN’s Manu Raju notes:

Not a surprise, but Tester is a no. He said he wanted to meet with Kavanaugh, who “couldn’t find the time” to meet with him in person. He’s the second red-state Dem up in 2018 to announce his opposition today

— Manu Raju (@mkraju) September 28, 2018

Tester’s locked in a tough fight against Matt Rosendale, too, with a three-point aggregate RCP lead. Tester didn’t cross for Gorsuch either, so this is more consistent — but it will also surely end up being a campaign issue for a state that Trump won by 20 points two years ago.

Still, the optics would be better for Senate Republicans if they could get a couple of Democrats to cross the aisle. The only two realistic pick-ups would be Heidi Heitkamp of North Dakota and Joe Manchin of West Virginia. Heitkamp has fallen behind GOP challenger Kevin Cramer in polling, in a state Trump won by 36 points, while Manchin has a comfortable lead over Patrick Morrisey (no relation) in a state Trump won by 42 points. A no on Kavanaugh would be very damaging for both candidates, and with the midterms less than six weeks away, they would have very little time to undo that damage.

Of course, all of this assumes that Susan Collins and Lisa Murkowski will vote for Kavanaugh. That seems more likely with Jeff Flake on board, but perhaps it’s best not to count chickens before eggs hatch, either.

Update: Just to underscore the risk for these Democrats:

Looking at some poll numbers this morning, it’s impossible to overstate how important the Kavanaugh hearings have been to voters. Like dropping a grenade into the electorate. Ds in red states are not going to like this.

— Josh Holmes (@HolmesJosh) September 28, 2018