Sen. Jon Tester (D-Mont.) on Tuesday announced he is blocking all of the Biden administration’s nominees to serve on Amtrak’s board of directors due to the lack of representation for Western states.

Tester made the announcement in a video on social media, noting that five of the nominees are from the Northeast corridor and none of the six is from the West. 

“Amtrak is not only critical to Montana, but it’s critical to rural communities and economies across this entire country, and it’s important that folks in rural America have a voice at Amtrak to make sure we aren’t left behind,” Tester said. “I’ll be blocking these nominees until rural America has a seat at the table.”

Tester added the bipartisan infrastructure law passed in 2021 “set clear geographic requirements” to ensure the entire country had representation on the Amtrak board.

“This slate of nominees fails to meet those requirements,” Tester said. “That’s the end of the story.” 

According to Tester’s office, the infrastructure law specified that no more than four of the nominees could be from the eight states and the District of Columbia that comprise the Northeast corridor.

He said all the nominees individually are qualified to serve on the board.

“But it is critical that we respect and follow the rules and laws plainly laid out when making these decisions,” Tester wrote in a letter to President Biden. 

The lone nominee from outside of the Northeast is Christopher Koos, who serves as mayor of Normal, Ill. 

This is not the first time Tester has complained about geographical representation on the Amtrak board. The Montana senator expressed his dismay at the lack of a nominee from the West during a September hearing before the Senate Commerce, Science and Transportation Committee. However, he said at the time that he didn’t “plan on stopping any of you from being on this board.”

Democrats hold a 14-13 advantage on the panel, meaning that Tester’s opposition would unilaterally keep these nominees from advancing to a full Senate confirmation if Republicans also put up a blockade. 

The White House did not immediately respond to a request for comment on Tester’s announcement.

The president has had a well-documented and lengthy relationship with Amtrak throughout his political career, having commuted from Wilmington to Washington during his years in the Senate. 

The move is also the second time a red state Senate Democrat up for reelection has thrown up a potential roadblock to Biden.

Sen. Joe Manchin (D-W.Va.) on Monday night threatened to back a full repeal of the Inflation Reduction Act, a bill he authored, over the Biden administration’s decision to “liberalize what we are supposed to invest in.” Manchin noted that the intention of the bill was to allow more investment in fossil fuel production over the next 10 years.

“If the administration does not honor what they said they would do and continue to liberalize what we are supposed to invest in over the next ten years, I will do everything in my power to prevent that from happening. And if they don’t change, then I would vote to repeal my own bill,” Manchin told Fox News’s Sean Hannity on Monday night.

Among the things Manchin could do is block the administration’s nominees from emerging through the Energy and Natural Resources Committee, which he chairs. 

Manchin and Tester are considered the most vulnerable Senate Democrats up for reelection next year. Manchin has not yet said if he will run once again, while Tester announced in February that he will seek a fourth term.