Nine Democratic senators facing re-election in November in states President Donald Trump 18 won months ago remain silent on the nomination of Richard Grenell as U.S. Ambassador to Germany ahead of the final vote Thursday. Grenell, who is openly gay, would be, if confirmed, among the highest ranking openly-gay U.S. government officials ever to serve.

Sens. Jon Tester (D-MT), Claire McCaskill (D-MO), Tammy Baldwin (D-WI), Bob Casey (D-PA), Debbie Stabenow (D-MI), Joe Manchin (D-WV), Bill Nelson (D-FL), Heidi Heitkamp (D-ND), and Joe Donnelly (D-IN) all have yet to go on the record as to whether they will vote to confirm Grenell, who once worked as a Mitt Romney campaign spokesman after he served as communications director for then-U.S. Ambassador to the U.N. John Bolton.

None of those Democratic senators’ offices have answered comment requests from Breitbart News when asked if they will vote for Grenell’s confirmation.

All are considered, to varying degrees, vulnerable to Republican challengers in the coming midterms.

Some more left-wing Democrats have actively been holding up Grenell’s nomination. One vector of attack is Grenell’s alleged “misogyny,” gleaned by these detractors from now deleted tweets suggesting MSNBC anchor Rachel Maddow “needs to take a breath and put on a necklace” and “Hillary [Clinton] is starting to look like Madeleine Albright.”

“I cannot in good faith support a nominee who has a lengthy track record of tweets attacking both prominent Democratic and prominent Republican women,” Sen. Jeff Merkley (D-OR) said last month on the Senate floor, for example.

Breitbart News asked all these Senators’ offices, along with Sen. Doug Jones (D-AL), who represents deep-red Alabama, if they would support Grenell, but none responded to the question.

Some have previously commented in passing on the Grenell nomination. “Would you vote for Grenell?” Radio Host Hugh Hewitt asked Heitkamp last month, for example.

Heitkamp was non-committal, answering, “Well, I haven’t actually looked at it,” adding, however, “But you know, if he gets, if he gets a floor vote, he’ll pass, obviously.”

Heitkamp has, however, said she will vote to confirm the more contentious pick of Mike Pompeo for Secretary of State. Pompeo’s vote is expected around the same time as Grenell’s vote.

Without these Democrats’ support, Grenell is still overwhelmingly likely to be confirmed to the post, which would be the most prestigious executive office ever held by an openly gay American. While there have been other U.S. ambassadors who are openly gay — including six appointed by former President Barack Obama — none have been for a country as strategically important to U.S. diplomacy as Germany.

Gay Republican groups and populist conservative voices have presented a united front of support for Grenell. The only possible Republican holdout is Sen. Rand Paul (R-KY), who also has not expressed an opinion on Grenell’s nomination on the record. Vice President Mike Pence is expected to be on hand to break a tie if need be.

This confirmation vote is likely to be a significant one on the campaign trail in 2018 in the midterm elections. A source close to the first family and a political adviser to the Trumps told Breitbart News that he would advise the president and first family campaign heavily this year against any red state Democrat who votes against Grenell.

Breitbart News’s Matthew Boyle contributed reporting to this story.