HOWELL, Mich. — The message printed on a pair of handmade wood-and-cardboard placards could not have been clearer as Representative Elissa Slotkin gazed out on a crowd of about 300 of her constituents who gathered for a town hall-style meeting to discuss their biggest concerns: “IMPEACHMENT INQUIRY NOW.”

“I just want her to know that some of her constituents are there,” said Patricia Onelio, 61, who staked out seats with her husband in the front row, determined for their demands to be seen by their congresswoman, a Democrat in a Republican-leaning district who has resisted calls to impeach President Trump. “He gets more emboldened by the minute, so I just think it’s important for us to show up and let her know where we stand.”

Here in this town about an hour northwest of Detroit that Mr. Trump carried by seven points in 2016, and in similar districts throughout the country where Democratic victories last year handed the party control of the House, lawmakers like Ms. Slotkin hardly need the reminder.

But while attendees had scrawled enough questions about impeachment on the index cards provided that the moderator immediately raised the topic, and returned to it a second time, there was little pushback to Ms. Slotkin’s wait-and-see approach.