If Bernie Sanders did win the U.S. presidency, it could prove bad news for U.S. billionaires. Elizabeth Warren is planning to levy taxes of up to 62 percent on the country's wealthiest people but Sanders' proposals go much further. That's according to a new interactive website developed by Emmanuel Saez and Gabriel Zucman from the University of California, Berkeley which shows presidential candidates' tax plans by income group.The data shows that while Sanders would tax the majority of income groups at a lower rate than the current tay system, it starts to increase dramatically when it comes to the top 1 percent of earners. It doesn't stop there and the country's 400 wealthiest individuals would have to pay 97.5 percent tax compared to the current 23.1 percent - bad news for people like Jeff Bezos and Bill Gates who would pay approximately $9 billion and $8.5 billion this year respectively.Sanders and Warren have made wealth taxes central to their campaigns and historically, such moves have proven popular with voters. Every year between 2013 and 2018, Gallup polling found that 60 percent or more of the U.S. public felt that upper-income people pay too little in federal taxes annually. Sanders tweeted yesterday that "billionaires should not exist" and that 500,000 Americans are homeless, 87 million are uninsured or underinsured and 45 million have student debt, all while three people own more wealth than the bottom half.