Colorado GOP establishment figures are lining up against Lauren Boebert as she faces a competitive primary in her district

• 3 GOP ex-senators endorsed one of Lauren Boebert's primary opponents, Jerry Sonnenberg.
• All of them also used to represent the district that Boebert's trying to carpetbag her way into.

As Rep. Lauren Boebert campaigns in her new Colorado district, establishment GOP figures who used to represent the area are lining up against her.

On Thursday, three former Colorado GOP senators — Cory Gardner, Wayne Allard, and Hank Brown — endorsed Logan County commissioner Jerry Sonnenberg, one of several opponents Boebert faces in the GOP primary.

All three ex-senators used to represent the 4th district, which covers the eastern portion of the state, in the House.

"He will be a passionate and dedicated warrior for our nation and our shared conservative values," Gardner said of Sonnenberg in a statement, calling him the "conservative conscience" of the district.

Sonnenberg, a former state lawmaker who rose to become the president pro tempore of the Colorado Senate, said the endorsements highlighted his deep roots in the district.

"Each of them knows the fourth district and understands the kind of principled leadership our community needs in Congress," said Sonnenberg.

Boebert, who currently represents a district covering the opposite side of the state, announced her decision to switch to the deeper-red 4th district at the end of 2023 — a move commonly known as "carpetbagging."

The congresswoman has argued that she was protecting her old constituents from an onslaught of Democratic spending after she won reelection in 2022 by less than 600 votes.

Boebert has been a controversial figure since her election in 2020, but she's faced ire from even Republicans after being ejected from the musical "Beetlejuice" in Denver last year for vaping and apparently groping a male companion.

While the congresswoman has the backing of national Republicans, the trio of endorsements from Sonnenberg shows the challenge she'll have in shoring up support in the new district ahead of the June primary.

During one recent debate, Boebert was asked by one of her opponents to define the word "carpetbagger."