Donald Trump in astonishing Twitter rant after Barack Obama wins US election We can't let this happen. We should march on Washington and stop this travesty. Our nation is totally divided! Lets fight like hell and stop this great and disgusting injustice! The world is laughing at us. He added: "This election is a total sham and a travesty. We are not a democracy! Our country is now in serious and unprecedented trouble...like never before. Our nation is a once great nation divided! The electoral college is a disaster for a democracy. He urged opposition politicians to "stay strong and never give up" and called for the termination of "Obamacare," the President's high-profile health insurance reforms. He also deleted a series of "Tweets" suggesting that Mr Obama beat Mitt Romney despite failing to win the popular vote, when it later transpired to be wrong. But his comments provoked a heated response, with celebrities including Alec Baldwin, a well-known Obama supporter, leading a backlash from thousands of users. The actor wrote: "@realdonaldtrump. You trust the voters when they choose The Apprentice. But not now? Steve Levitan, the executive producer of smash-hit comedy wrote: "Hey Trump, did you see Mitt Romney's concession speech? That's what graciousness and good hair looks like. Meanwhile Brian Williams, the NBC News anchor, also criticised Mr Trump - whose reality show is aired by the same network - on-air, saying he was "driven well past the last exit to relevance." He told viewers: "This is, as they say, out there and getting an airing tonight, so you might as well know about it. Donald Trump, who has driven well past the last exit to relevance and veered into something closer to irresponsible here, is tweeting tonight. Here's a sampling... He then read out some posts. During the bitter campaign, Mr Trump made a number of farcical interventions including a bizarre "deal" to donate $5 million to charity should President Obama agree to release his college and passport records. Appearing on The Tonight Show with Jay Leno during the campaign, Mr Obama said he had never met Mr Trump, joking that their rivalry could be dated back to their time together "in Kenya." The Apprentice star has also considered a Republican presidential run. Tonight he posted messages about the Hurricane Sandy relief efforts in his home town of New York. Donald Trump offers Barack Obama $5m to release college and passport records