House Democrats reportedly are considering whether to pursue in their impeachment inquiry matters arising from the Mueller investigation. Specifically, they are looking at whether President Trump lied to Robert Mueller.

The Washington Post’s report on this development is based on representations made by House Democrats to the federal appeals court in Washington, D.C. The Dems told the court that they need secret grand jury evidence from the Mueller probe to be released in order to consider, as part of their impeachment inquiry, whether Trump lied to Mueller.

Are the Democrats telling the truth to the court or are they just using the existence of the impeachment inquiry to pry loose secret testimony they have long wanted? According to the Post, Democrats had privately been playing down the suggestion that the Mueller investigation is likely to be part of articles of impeachment.

But now, again according to the Post, Democrats are debating whether articles of impeachment should include obstruction of justice allegations stemming from the Mueller investigation and report. The usual suspects are taking their usual sides. Nancy Pelosi wants to keep the focus on Ukraine. Hard leftists want to bring in Mueller. They can’t let go.

The hard leftists say the Roger Stone trial provides fuel for obstruction of justice charges against Trump. They point to testimony by former deputy Trump campaign manager Rick Gates that Stone spoke to Trump regarding Stone’s efforts to learn about WikiLeaks’ plans. Trump told Mueller, in written responses to questions, that he did not recall discussing WikiLeaks with Stone.

It’s clear that these two pieces of testimony, which aren’t really inconsistent, don’t bolster an obstruction of justice claim. It’s equally clear, I think, that Nancy Pelosi is right. The Democrats should keep their impeachment focus on Ukraine. The public has a strong sense that the Mueller probe is old news and that it failed to find real wrongdoing.

Indeed, trying to revive Mueller-related claims would play into the hands of Republicans who argue that the Ukraine inquiry is the continuation of the fruitless Russia probe. In other words, another chapter in the ongoing effort to impeach Trump over something — anything.

Republicans are right about this, but it doesn’t follow that there’s nothing to the Ukraine probe. However, if the Democrats’ impeachment theory includes Mueller-related and Ukraine-related counts, the public may perceive them as part of the same resistance stew.