Peter Strzok - the Federal Bureau of Investigation special agent who was heavily criticized by President Trump, the president's allies and a blistering Justice Department Inspector General report - has officially been fired from the Federal Bureau of Investigation, according to his lawyer.
"This decision should be deeply troubling to all Americans".
In one exchange, Ms Page asks: Trump is "not ever going to become president, right?"
Strzok worked on FBI investigations into both campaign opponent Hillary Clinton's use of an email server and potential co-ordination between Russian Federation and Trump's campaign.
President Donald Trump has repeatedly cited the texts between Page and Strzok, who were dating during the 2016 campaign, as proof that the FBI's investigation was tainted from the start.
"The decision to terminate was taken in response to political pressure, and to punish Special Agent Strzok for political speech protected by the First Amendment, not on a fair and independent examination of the facts", he said.
The FBI didn't immediately respond to requests for comment. Strzok and Page were having an affair at the time the messages were sent.
The FBI agent Strzok was texting, Lisa Page, has also since left the FBI on her own accord.
Rather than probe the newly discovered emails, Strzok opted to further investigate possible collusion between members of the Trump campaign and Russian operatives. The list of bad players in the FBI & DOJ gets longer & longer.
The delays were merely the "result of bureaucratic snafus", Strzok's lawyer wrote last month in USA Today.
His deputy Andrew McCabe was removed by Attorney General Jeff Sessions after an inspector general determined that he had made unauthorised leaks to the press about the Clinton investigation.
McCabe - who, unlike Comey, could not be removed at the will of the president - has said his termination was a politically motivated attempt to undermine the Mueller probe. The inspector general, who uncovered the messages, found no evidence that the pair imposed their political views on their investigative decisions but cited that exchange as "not only indicative of a biased state of mind but, even more seriously, implies a willingness to take official action to impact the presidential candidate's electoral prospects".