CNN invited a reporter from San Diego's KUSI TV station to discuss border walls.Dan Plante was to report on how border barriers were useful.But CNN never aired the segment, and KUSI accused CNN of political bias on Thursday. President Donald Trump echoed KUSI's accusation on Twitter.On Friday, KUSI rowed back its comments, with its news director saying that he didn't actually know why CNN rejected the story.San Diego TV station KUSI-TV accused CNN of turning down an appearance from a reporter that they originally solicited on how border walls are useful because the national network allegedly didn't like what the reporter had to say. Friday, the station backtracked, saying the reporter, Dan Plante, didn't actually know why the rejection happened.CNN reached out to Plante to talk about a border barrier in San Diego for a segment meant to air on Thursday, the Associated Press (AP) reported.The segment was to be in relation to President Donald Trump's proposed, $5.7 billion border wall along the US-Mexico border. Congressional Democrats have for weeks refused to fund the wall, which caused the federal government to partially shut down last month.But Plante's report never aired on CNN, and KUSI accused CNN of political bias.KUSI's digital content manager, Mike McKinnon III, wroteon Thursday: "We believe CNN declined a report from KUSI because we informed them that most Border Patrol Agents we have spoken to told us the barrier does in fact work.""We have continuously been told by Border Patrol Agents that the barrier along the Southern border helps prevent illegal entries, drugs, and weapons from entering the United States, and the numbers prove it," McKinnon added.KUSI anchor Anna Laurel added in her segment that day: "They didn't like what they heard from us."Trump also backed KUSI by tweeting its segment on the border barrier and CNN's rejection, adding: "#FakeNews." The president has routinely and publicly criticized CNN, claiming it was biased against him.But KUSI rowed back its comments on Friday, with news director Steve Cohen saying he actually didn't know why the network turned down Plante's appearance."It's certainly plausible that they didn't want it for the viewpoint, or they just didn't want it," Cohen said, according to the AP. "Both are plausible conclusions. I made one rather than the other."We called several local stations to book someone for a show. We didn't end up booking any of them. That happens many times every single day. We did, however, book a reporter from KUSI for a story on immigration and the border wall in November. This is a non story. #factsfirst'' CNN Communications (@CNNPR) January 11, 2019CNN, on its part, said it routinely cancels bookings and called the saga a "non story."Its communications team tweeted on Friday: "We called several local stations to book someone for a show. We didn't end up booking any of them. That happens many times every single day. We did, however, book a reporter from KUSI for a story on immigration and the border wall in November. This is a non story."The government shutdown entered its 22nd day on Saturday, making it the longest in US history. It does not appear close to ending as Trump and Democratic leaders have yet to find an agreement. 800,000 federal workers remain left with no paychecks.Read more on the government shutdown and proposed border wall:From airport lines to food inspections, here are all the ways the government shutdown is impacting the lives of average AmericansHere's what would happen if Trump declared a national emergency to build his border wallGoFundMe is refunding all donations made to the 'Fund the Wall' campaignA journey along the entire 1,933-mile US-Mexico border shows the monumental task of securing itJoin the conversation about this storyNOW WATCH: MSNBC host Chris Hayes thinks President Trump's stance on China is 'not at all crazy Click here to read full news..