This is an opinion column.

President Donald Trump is absolutely entitled to an attorney general who runs the Department of Justice consistent with executive branch priorities. Attorney General Jeff Sessions has unequivocally done that on issues ranging from immigration enforcement to protecting religious liberty and combatting violent crime. But that's not enough. Trump wants a fixer, and Sessions isn't willing to be one.

"Fixers," like former Trump attorney Michael Cohen, make inconvenient problems disappear for their clients. The expectation is that a fixer loyally protects his or her patron by any means necessary.

Unfortunately for Trump, serving as the president's fixer isn't part of the attorney general's job description. Even so, Trump's ire is almost singularly focused on the fact that Sessions properly recused himself from matters related to the 2016 campaign.

The president isn't hiding his desire to end Special Counsel Robert Mueller's investigation and install someone who behaves more like Cohen than Sessions. Trump's ideal attorney general would either end Mueller's investigation or take control of it in a manner that insulates Trump and his inner circle.

After all, that's what fixers do. Attorney generals don't...or at least they shouldn't.

In his most pronounced response to Trump's continued media harassment, Sessions bluntly stated, "While I am attorney general, the actions of the Department of Justice will not be improperly influenced by political considerations."

Trump responded that Sessions made such a statement "because he doesn't understand what is happening underneath his command position."

Sessions does understand that the attorney general shouldn't make prosecution decisions based on political impulse and popular opinion.

Trump has repeatedly called for Sessions to investigate the "other side" or weed out corruption in a manner that assumes Sessions isn't doing so already. As laws applied to facts justify federal prosecution, Sessions and his United States attorneys should absolutely do so. They probably won't go on Fox & Friends to talk about those investigations. That is how federal laws enforcement should work. It's a far different process than launching into investigations and prosecutions because a talking head on cable news or a presidential tweet demands it.

The DOJ has already taken a look into matters the president continues to raise.

For example, the DOJ inspector general's report from June exhaustively discusses whether impermissible political bias impacted department decisions related to Hillary Clinton's use of a private email server. It details former FBI Director James Comey's insubordination, but it did not find "evidence that improper considerations, including political bias, directly affected the specific investigative decisions."

In spite of the thorough report addressing many of Trump's allegations lobbed at the Department of Justice, Trump continues his media barrage as if reliable answers aren't readily available. The political narrative takes precedence over reality.

Again, Trump should absolutely fire Sessions if he has credible evidence that federal laws aren't being faithfully enforced or corruption is actually going unchecked. The processes, procedures and outcomes at the DOJ related to many of Trump's concerns simply fail to justify that conclusion.

We can't let the DOJ be about politics. Period. That conclusion shouldn't change because operatives in the prior administration were bad actors. We wouldn't allow a CEO to claim that his embezzlement is justified because his predecessor did it as well. Arguing that justice may depend on political context rejects America's longstanding tradition of independently upholding the rule of law.

If Sessions's cardinal sin is indeed refusing to be Trump's fixer, Republicans should defend him vigorously. At the same time, the attorney general does serve at the pleasure of the president. The Senate must thoroughly question Sessions's ultimate successor about the role of politics in the application of justice. Session's won't be the president's "fixer;" we must ensure the same can be said of our next attorney general as well.

Cameron Smith is a regular columnist for AL.com and vice president for the R Street Institute, a think tank in Washington, D.C. He previously served as counsel for Jeff Sessions on the Senate Judiciary Committee.