Photo: Tom Williams/CQ-Roll Call, Inc via Getty Images Rep. Sheila Cherfilus-McCormick's resignation has some Democrats fuming about what they say was an unfair process and even expressing buyer's remorse about voting to expel George Santos from Congress. Why it matters: Lawmakers' frustrations about a lack of due process in both cases threatens future efforts to remove House members over accusations of grave misconduct. Rep. Nancy Mace (R-S.C.) told Axios she will "do [a] privileged motion next week" to force a vote to expel Rep. Cory Mills (R-Fla.) over allegations of domestic abuse, financial misconduct and stolen valor. But even some Democrats say they are not comfortable taking such drastic action against Mills while he remains under investigation by the House Ethics Committee. Mills, who has denied the allegations, told Axios' Kate Santaliz on Tuesday that — unlike Cherfilus-McCormick (D-Fla.) — he will not resign.…