Its a pretty clear First Amendment violation, firing Peter Strzok. The President and Rep. Meadows have made some hay about Agent Strzok supposedly using influence in regard to the Mueller investigation into Pres. Trump. But, there has been no evidence of Strzok allegedly using his influence to affect the investigation. Agent Strzok specifically said “we will stop” the election of Pres, Trump in 2016. He said he was talking about “we” the voters. That was protected speech by a federal employee. See CBS news report here.
In firing the FBI agent and linking the firing to his comments about the President, the employer has set up a lawsuit nicely for the agent, if he wishes to pursue it. It was very unwise of the FBI to fire him for unsupported reasons. If the President and others could show actual influence over the investigation, my opinion would change. But, for now, there is no evidence of him exerting any actual influence over the investigation. Too, as he pointed out when he testified to Congress, if he wanted to affect the outcome of the 2016 election, he could have leaked the fact that the Trump campaign was being investigated in 2016.
Firing the agent may have placated some folks in the Executive branch, but that short-term gain may result in long-term pain.