Former New York City Mayor Michael Bloomberg is expected to enter the 2020 U.S. presidential race, reversing his previous decision.<br />A Bloomberg aide said on Thursday that the billionaire is reconsidering as he worries the current Democratic candidates are not "well positioned" to defeat President Trump.<br />The adviser added Bloomberg has not made a final decision yet, but he's reportedly preparing to file paperwork to qualify for the Alabama primary before Friday's deadline.<br />Given his more centrist views and vast fortune, Bloomberg's entry could pose a serious challenge to the current crop of Democrat candidates, including former Vice President Joe Biden.<br />