A group of prominent anti-Trump conservatives on Friday released a new ad that urges GOP senators to conduct a fair impeachment trial of President Donald Trump over the Ukraine scandal.

The Lincoln Project demands in the caption for its video that Republican lawmakers “consider the impeachment charges against Trump on their merits” instead of simply taking sides along party lines.

Senators must uphold their sworn oaths to “support and defend the Constitution of the United States against all enemies, foreign and domestic,” the project adds.

The ad itself shows footage of Senate Majority Leader Mitch McConnell (R-Ky.) and Sen. Lindsey Graham (R-S.C.) stating they’ve already decided to support Trump in the trial, as the following text appears:

President Donald Trump thinks he’s above the law. He believes he’s untouchable. Senate Republicans want to prove him right. They know who Trump is. They’ve forgotten their oaths. Let’s remind them.

It then encourages people to sign a petition demanding a fair trial.

Check out the clip here:

The Lincoln Project, which aims to end Trump’s presidency at the ballot box in November, was launched by George Conway, the husband of White House counselor Kellyanne Conway, and anti-Trump GOP strategists Rick Wilson, Steve Schmidt and John Weaver.

“We do not undertake this task lightly, nor from ideological preference. We have been, and remain, broadly conservative (or classically liberal) in our politics and outlooks,” they wrote in a New York Times op-ed last month. “Our many policy differences with national Democrats remain, but our shared fidelity to the Constitution dictates a common effort.”

Last week, the group called out evangelical Christians who support Trump with this spot:

It also attacked Sen. Cory Gardner (R-Colo.) as “just another Trump servant: weak, frightened, impotent” in this ad last Monday: