Well, for one, his sprawling district is located in western Minnesota.
2. He was targeted by the GOP in 2018, and his margins of victory have been shrinking lately. Peterson, 75, has held the seat since 1991.
3. Trump lost Minnesota by 1.6 percentage points but trounced Clinton by more than 30 percentage points in the 7th CD.
4. Minnesota's 7th congressional district is now part of Trump's America.
Source: Daily Kos
Compare the map above with this one.
Meet the Democrats Who Broke Ranks on Impeachment. (The New York Times, 10/31/2019)
In Peterson's case, it appears to be all about self-preservation. Mr. Peterson said in a statement that he had “some serious concerns with the way the closed-door depositions were run,” and had been inundated with calls from his constituents in the week leading up to the vote.
“Without support from Senate Republicans, going down this path is a mistake,” he said, calling the process “hopelessly partisan.”
Why Democrat Jeff Van Drew broke ranks on the impeachment inquiry vote. (11/3/2019)