Of all the questions raised by former special counsel Robert Mueller's investigation into Russia's interference in our 2016 elections, none has proven more mystifying and aggravating as to why Robert Mueller ultimately punted the question of whether President Trump committed obstruction of justice to Attorney General William Barr.

Mueller clearly deliberated and decided that not enough evidence existed to charge Trump with any conspiracy charges, yet he explicitly refused to come to a conclusion on the obstruction question. Of all the material benefit to the public brought by Mueller's hearings with the House Judiciary and Intelligence Committees, the only real question that matters to the public is why.

Mueller went through great lengths to obfuscate his intentions and understandably so. As special counsel, Mueller was assigned to make a legal decision, not a political one. Following the precedent set by the Office of Legal Counsel, Mueller has consistently maintained that even if he found enough evidence to charge Trump with acts of obstruction, he wouldn't charge a sitting president. But he refused to decide that "even if" question. His words today further indicate that he did believe Trump should have been brought up on obstruction charges otherwise, and his actions point towards his refusal to make a political decision by proxy and give Democrats the green light to initiate impeachment proceedings.

"Based on Justice Department policy and principles of fairness, we decided we would not make a determination as to whether the president committed a crime," Mueller states in his prepared remarks. The phrasing here is key. The Justice Department policy directed Mueller not to bring up charges, but it certainly doesn't say that Mueller couldn't or shouldn't make a verdict on whether Trump ought to be brought up on charges once he's out of office. No, that he blames on the intentionally vague "principles of fairness" doctrine. What does it mean? Likely that Mueller believes that he shouldn't be responsible for instigating political trials, only criminal ones.

Every equivocation indicated that Mueller personally believes Trump should face obstruction charges. When Rep. Ted Lieu, D-California, got Mueller to confirm that he believed Trump committed all three legal elements required to constitute obstruction of justice, Mueller attempted to halt the correlation by noting that he doesn't endorse the conclusion of what Lieu "was saying." But to both Lieu and Hakeem Jeffries of New York, Mueller concurred that Volume II of the report indicates that Trump committed all three elements of obstruction.

If Democrats genuinely believe they have the goods to impeach Trump on obstruction charges, they'll need to initiate proceedings without having Mueller's explicit approval. The former special counsel made abundantly clear he refuses to make that decision for them, and although he should have answered the obstruction question as a matter of legal principle, it makes sense why he wouldn't as a moral one.

Democrats won't get Mueller as a scapegoat. If they go forward with impeachment, they'll have to prove to an overwhelmingly unapproving public why they have the political points to do so.