Former Democratic vice presidential nominee Joe Lieberman told CNBC on Thursday that President Donald Trump’s campaign has the right to file lawsuits challenging state election outcomes. However, the former U.S. senator from Connecticut said he hopes that Trump takes lessons from how Al Gore handled the hotly contested 2000 election that went to the Supreme Court if the litigation does not go his way.”You’ve got a right to take your case to the courts. Let the judges decide. But most of all, as Al Gore did in 2000, it has got to end at some point for the good of the country,” Lieberman said on “Squawk Box.” “You’ve got to have a transfer of power and pull together.” Lieberman has endorsed Democrat Joe Biden in the 2020 race against the incumbent Trump.The Trump campaign is pursuing legal action over vote counting in a number of closely watched states, including Michigan, Georgia and Pennsylvania. NBC News projects Biden as the winner of Michigan’s presidential contest, but it has not made a call yet in Georgia and Pennsylvania. The Trump campaign also wants a recount in Wisconsin, where Biden is the apparent winner, according to NBC News.Biden has 253 electoral votes, compared with Trump’s 214, in the battle for the 270 needed to win the presidency, according to a tally from NBC News.Lessons from Bush-Gore election in 2000Lieberman was Gore’s running mate in the 2000 election, which featured Bill Clinton’s vice president against Republican challenger, then-Texas Gov. George W. Bush. The race between Gore and Bush came down to the razor-thin vote margin in Florida. A protracted legal battle over recount efforts in the state ensued. It took more than a month after Election Day until the Supreme Court, in Bush v. Gore, overturned a decision from the Florida Supreme Court that ordered a recount of the votes.The decision from the nation’s highest court effectively gave Bush a 537-vote victory in Florida and, by extension, enough electoral votes to become president. “While I strongly disagree with the court’s position, I accept it,” Gore said at the time, according to the Associated Press.On Thursday, nearly two decades later, Lieberman recalled what happened next. “After the decision that night, our lawyers had a disagreement. Some of them said, ‘That’s it. No more legal roads open.’ And some said, ‘You can go back to the Florida Supreme Court and ask them to implement the statewide recount that they ordered just a few days ago.'”While calling the Supreme Court’s decision “very painful, shocking, disappointing,” Lieberman said that Gore at the time was deeply concerned about the implications of further drawing out the legal fight and potentially complicating the transition-of-power timeline. Gore officially conceded the election to Bush on Dec. 13, 2000.”I say to President-elect Bush that what remains of partisan rancor must now be put aside, and may God bless his stewardship of this country,” Gore said then, according to a transcript from The New York Times.”I hope that the litigants, the candidates, the parties now, will remember that lesson. It’s a very strong one, from Al Gore really. I give him the credit,” Lieberman told CNBC on Thursday.