Calling Sinema an Obstacle to Progress, 5 Veterans Quit Her Advisory Council

“Democrats were out desperately trying to help her win the seat, and now we feel like, what was it for?” Sylvia González Andersh, one of the veterans who signed the letter, said in an interview. “Nobody knows what she is thinking because she doesn’t tell anybody anything. It’s very sad to think that someone who you worked for that hard to get elected is not even willing to listen.”

Ms. Andersh is featured in the advertisement reading aloud the resignation letter, with its harsh assessments of Ms. Sinema. Common Defense, which in recent weeks placed a seven-figure ad buy to pressure Ms. Sinema to support the reconciliation bill, said it would invest another seven figures to aid the new spot.

Ms. Sinema said in a statement that she would “always remain grateful for these individuals’ service to our nation,” and had valued their input to her work.

“While it is unfortunate that apparent disagreement on separate policy issues has led to this decision,” she said, “I thank them for their service and will continue working every day to deliver for Arizona’s veterans who have sacrificed so much to keep us safe and secure.”

A spokeswoman for Ms. Sinema said the senator and her team had engaged in “many” policy discussions with members of the advisory council on a number of issues, including those related to veterans.

Ms. Sinema has come under mounting pressure in recent weeks. She has been mobbed at airports and followed into a restroom by progressive activists who say she is blocking once-in-a-generation change and refusing to meet with them to explain why.

Ms. Sinema condemned the bathroom encounter as “wholly inappropriate” and suggested that it was, at least in part, a result of the heated debate that has surrounded Mr. Biden’s agenda. But she has not found a chorus of defenders from her own party. Top Senate Democrats failed to reach agreement on a statement of outrage on her behalf.