Donald Trump has become the third U.S. president in history to be impeached, but what may be even more notable is that the 73-year-old Republican will be the country's first president to seek re-election after the dramatic rebuke from Congress.

While Trump's job rating has been stable even since the impeachment inquiry began in September, the political fallout of seeking to oust a president as the 2020 election looms — an issue that has deeply divided the public — is unclear, experts say.

Trump was impeached by the Democratic-controlled House of Representatives for allegedly abusing the power of his office by pressuring Ukraine to investigate a key political rival in the presidential election, as well as for obstructing Congress during its impeachment inquiry.