Mr. Dobbs, a loyal supporter of former President Donald J. Trump, was named in a $2.7 billion lawsuit filed on Thursday against the Fox Corporation and two other Fox anchors.Lou Dobbs had the top-rated show on Fox Business. It was canceled the day after he was one of three Fox anchors named in a lawsuit filed by Smartmatic, an election technology company.Lou Dobbs had the top-rated show on Fox Business. It was canceled the day after he was one of three Fox anchors named in a lawsuit filed by Smartmatic, an election technology company.Credit…John Lamparski/Getty ImagesMichael M. GrynbaumBy Michael M. GrynbaumFeb. 5, 2021Lou Dobbs, one of former President Donald J. Trump’s most loyal media supporters, abruptly lost his pulpit on Friday when Fox Business canceled his weekday television show, which had become a frequent clearinghouse for baseless theories of electoral fraud in the weeks after Mr. Trump lost the 2020 presidential race.Mr. Dobbs’s decade-long tenure at the network ended with little warning — a guest host filled in for his Friday slot — only a day after the election technology company Smartmatic filed a defamation lawsuit against Rupert Murdoch’s Fox Corporation and Fox News.The suit, which seeks damages of at least $2.7 billion, also named Mr. Dobbs as an individual defendant along with two other Fox anchors, Maria Bartiromo and Jeanine Pirro. Smartmatic specifically cited Mr. Dobbs’s program, which by late last year had become so packed with falsehoods about Mr. Trump’s defeat that Fox Business was forced to run a fact-checking segment debunking some of its own anchor’s assertions.Executives at Fox did not elaborate on Friday about why they had canceled Mr. Dobbs’s program, which was the top-rated show on Fox Business and drew a bigger audience than its competition on CNBC. The network said in a statement that it regularly reviewed its programming lineup.