I have criticized much in Bill Clinton’s conservative record, and certainly am not defending Clinton out of any partisan loyalty, but the Republican defense of Trump’s firing of James Comey because Bill Clinton fired an FBI director does not hold up. Clinton acted in a bipartisan manner, basing his actions on an investigation which started under George H. W. Bush. He fired William Sessions over financial improprieties, not because the FBI director was investigating his administration. When the FBI director he appointed began to investigate him, perhaps Clinton wished he could fire him, but he did not.
It remains unprecedented for a president to fire an FBI director while his administration was under investigation, violating principles of justice and of the independence of the FBI.
Vox looks at Bill Clinton’s actions in far greater detail. I discussed the firing of James Comey, including several other opinions, here and here.