Sen. Tammy Duckworth (D-IL) announced Thursday that she would block the promotions of 1,123 senior military officers until Defense Secretary Mark Esper promises that he will promote Army Lt. Col. Alexander Vindman, who is believed to have communicated with the “whistleblower” that sparked Trump’s impeachment. Her office called the move “unprecedented” but said it came in response to reports of “political interference in military matters” by Trump — the commander in chief.