Last week, Sen. Joe Manchin was angry. The Democratic senator had seen a TV ad run by GOP Rep. Alex Mooney — the Trump-backed candidate in a primary for a US House seat in West Virginia —- suggesting that his Republican opponent, Rep. David McKinley, backed President Joe Biden"s sprawling social spending agenda. So he called up McKinley and told him he"d be willing to cut a TV ad and call out Mooney, a rare move to insert himself into a GOP primary. Manchin told CNN that he informed McKinley he"s willing to do this "because I"m pissed off" after seeing "someone who doesn"t know my state and is lying" about the Republican congressman"s record. "You"re telling me he"s concerned about my state? ... And that"s when I just said, "Enough is enough," " Manchin said in a phone interview. "I"m happy to do something to correct that lie. It"s truly a lie." Manchin"s comments, which come ahead of next week"s rare GOP-member-vs.-member battle caused by redistricting, are in reference to the bipartisan infrastructure law. Trump backed Mooney after McKinley joined a dozen of his House GOP colleagues — along with West Virginia"s Shelley Moore Capito and 18 other Senate Republicans — to vote for the bipartisan law to pour money into roads, bridges and broadband. But a majority of congressional Republicans voted against it as they contended it was wasteful and were urged by Trump to kill the bill. Mooney, who used to serve in the Maryland state senate and chaired the Maryland GOP, is seen as a potential 2024 opponent to Manchin"s expected reelection bid. He has cut several ads in his primary race, accusing McKinley of backing Speaker Nancy Pelosi"s "socialist agenda" and Biden"s "trillion dollar spending spree." "President Trump warned us about RINOs, sellouts and known losers. David McKinley proved him right," the narrator says in one Mooney ad. Manchin, who backed the infrastructure law, was single-handedly responsible for derailing Biden"s multi-trillion social spending agenda — known as Build Back Better — which he is now touting in West Virginia. And Manchin said he"s angry at Mooney"s effort to conflate the Build Back Better plan — which McKinley opposed — and the infrastructure law, which had bipartisan backing. Manchin says he"s perturbed because "of all the s*** we got for separating" the two bills even as House progressives last year demanded for months that the two bills be tied together. "Every part of the state is tickled to death in knowing what they want to get repaired ... for the first time in 30 or 40 years," Manchin said of the infrastructure law. "But what Mooney is trying to do is lump one with the other. That is an outright lie." Manchin accused Mooney of voting against the plan because he "thought it was a good political message for him." The ad, released over the weekend, features Manchin looking straight into the camera and saying that McKinley has opposed "reckless spending because it doesn"t make sense for West Virginia," as Manchin noted he also opposed the Build Back Better plan. "Alex Mooney has proven that he"s all about Alex Mooney," Manchin said in the ad, which the McKinley campaign says is running on broadcast TV in West Virginia markets and cable in Washington. A Mooney campaign spokesperson didn"t respond to a request for comment Monday. But Mooney tweeted his criticism at Manchin and McKinley over the ad, saying that Manchin"s backing is "further proof that David McKinley is a complete and total RINO," referring to the attack of being a "Republican in name only." "It is not surprising that Joe Manchin and the Democratic Party want to defeat a principled conservative like me," Mooney added. Capito, the West Virginia Republican, said of the Manchin ad: "I"ve given up a long time ago trying to figure out what Joe Manchin is doing." Manchin says he has a 40-year relationship with McKinley, dating back to their time in the West Virginia statehouse. And he said they"ve crossed paths numerous times in their political careers, including in 1996 when they both lost their parties" respective primary bids for governor. And while he said they, along with their wives, have become friends, he says he "never" would have gotten involved in this GOP House primary until he saw the Mooney ad that was cut. Manchin says he hasn"t taken similar action in a GOP primary before, but said he"d be willing to cut an ad on behalf of GOP Sen. Lisa Murkowski in Alaska if she asks him for help in her race. Manchin"s move could also been seen as an opening salvo for his reelection bid. In the interview, the 74-year-old Manchin sounded like he planned to run again, saying: "My inclination is I want to do all I can to continue to help this country and my state." Asked if Manchin could be vulnerable in 2024, Capito said Monday: "It"s going to be tough." And it remains to be seen if he could face Mooney. In an interview late last year, Mooney downplayed the possibility of him challenging Manchin in 2024, saying: "I gotta win May 10," referring to next week"s primary. Manchin said he didn"t cut the ad against Mooney because he sees him as a prospective challenger, but said if Mooney wants to run against him, "he"ll have to saddle up and get in line." And if Mooney loses in next week"s primary, Manchin said: "He may look back at Maryland and think it"s advantageous to go back across the state line." — CNN