WASHINGTON — In a year where on-ramps for ducks and the specifics of the president’s theoretical plans for a see-through wall along the United States border are in dispute, the list of only-in-2017 questions one could ask a lawmaker grows by the day.

“How many times have you been challenged to a duel?” just rose to the top.

“I’ve been in the Senate for 20 years,” Susan Collins, Republican of Maine, said in a brief interview at the Capitol on Tuesday. “I have never, ever had anyone suggest a duel as a way to solve a dispute.”

Ms. Collins was responding to a suggestion from Blake Farenthold, a Republican congressman from Corpus Christi, Tex., that an “Aaron Burr-style” duel be used to settle disagreement over health care with “female” senators.

“If it was a guy from South Texas,” Mr. Farenthold told a Texas radio station on Friday, “I might ask him to step outside and settle this Aaron Burr-style.” Ms. Collins and two other colleagues — yes, all were women — voted last week against a full repeal of the Affordable Care Act.