A group of Senate conservatives is demanding help from Mitch McConnell on forcing a full impeachment trial for Homeland Security Secretary Alejandro Mayorkas, Axios has learned.

Why it matters: Senate Democrats will control the process. But the historic impeachment articles are proving to be the next flashpoint for the GOP minority leader.

• 13 Republicans, led by Sens. Mike Lee (Utah) and Ted Cruz (Texas), plan to send a letter to McConnell on Tuesday morning, demanding they "fully engage our Constitutional duty and hold a trial."
• A Democratic effort to dismiss the impeachment articles would be "an action rarely contemplated and never taken by the U.S. Senate," the senators argue in a copy of the letter first obtained by Axios.
• If the tables were turned, "the opposition would be fierce and the volume from Democrats would be deafening," they write.

Zoom in: Lee and Cruz met quietly with the Senate parliamentarian a week ago, arguing that Majority Leader Chuck Schumer (D-N.Y.) should not be able to simply set aside the historic impeachment articles so early in the process, Lee told Axios.

• The parliamentarian, whose job is to interpret Senate rules and precedent, has not yet provided them any kind of formal response.
• Lee told Axios he doesn't know where GOP leadership will end up, but he hopes they aren't "complicit in the Democrats' effort to just table the motion as if this were some childish, sophomoric exercise."
• Cruz told Fox News it's a chance for GOP leaders to "demonstrate some backbone."

Schumer hit back at Cruz's comments, saying Cruz "is the one who wants to do nothing on the border" by voting against the bipartisan border deal.

Between the lines: McConnell told CNN he hasn't "really thought about it" when asked about a vote to dismiss the charges. That vote would require a majority instead of the 2/3 required to convict during an impeachment trial.

• "I don't think we'll have two endless trials like we've had recently," McConnell added, in reference to Democrats likely ending things quickly.
• As conservatives push for trial, other Senate Republicans have criticized a rise in "snap impeachments" and indicated they do not see any "high crimes or misdemeanors."
• Sen. Kevin Cramer (R-N.D.) recently called the articles "dead on arrival" and the "dumbest exercise and use of time."

The bottom line: Conservatives' distrust has boiled over after the failed border deal and fraught process to pass the foreign aid package.