Michael Bloomberg’s decision to enter the Democratic Primary reveals a lot about the state of the two party system that has dominated American politics for over 150 years. Similarly, he was first elected mayor as a Republican in 2001 and only rejoined the Democratic Party in 2018.for michael Bloomberg, or any other rational but conservative person, the Republican Party is no longer a viable homeThe question this raises is why Bloomberg to chosen to run as a Democrat. Trump will be renominated by the Republican Party, so the only way to replace him is to run for the Democratic nomination. The reason this will not happen is that for Bloomberg, or any other rational but conservative person, the Republican Party is no longer a viable home. A Republican Party that was interested in competing in, and winning, elections would welcome people like Bloomberg, although not necessarily the primary challenge to a sitting president.