The political action committee associated with the gun violence prevention organization co-founded by former U.S. Rep. Gabrielle Giffords hit the airwaves in Colorado Tuesday with an ad tying Republican U.S. Sen. Cory Gardner to President Donald Trump and his opposition to requiring universal background checks on gun sales.

The 30-second ad is the first salvo in a $1.25 million campaign Giffords PAC announced earlier this month it would be waging to defeat Gardner, who is seeking a second term.

Giffords, the former Arizona congresswoman and shooting survivor, and her organization endorsed Gardner’s Democratic challenger, former Colorado Gov. John Hickenlooper, in March.

“What happened to Cory Gardner? Gardner promised he’d put Coloradans first, but then he had a change of plans,” says the ad’s narrator, as an actor who bears a resemblance to Gardner replaces “Colorado” with “Trump” on a yard sign and bumper sticker.

Calling Gardner one of Trump’s “most loyal followers,” the ad says the Republican “even stood with Trump to stop background checks that would keep guns away from dangerous people,” referring to Gardner’s stance last summer when Trump had a change of heart after initially saying he supported background-check legislation.

“When it comes to preventing gun violence, Cory Gardner is worse than Donald Trump’s carbon copy – he’s Trump’s lackey,” said Peter Ambler, executive director of Giffords. “This campaign to elect gun safety champion John Hickenlooper is a defining piece of our national efforts to relegate the gun lobby’s grip on Congress to the dustbin of history.”

A spokeswoman for the Gardner campaign declined to comment on the ad.

Giffords PAC said in a release that it plans to spend more than $7.5 million to elect allies this cycle. In 2018, the group spent more than $2 million in opposition to Republican U.S. Rep. Mike Coffman, who was elected as Aurora’s mayor last fall after losing his seat in Congress a year earlier.

The group said recent polling it commissioned found that nearly two-thirds of suburban women in Colorado and four other swing states say they will never vote for candidates who don’t support “requiring background checks on all gun sales.”