Robert S. Mueller III filed a lengthy report that concludes among other things that the president of the United States obstructed justice regarding the lengthy investigation into the Russia Thing.

If a president can be impeached for obstruction of justice in 1998, why is it different in 2019? That’s the quandary with which I am wrestling at this moment.

House Republicans declared in 1998 that a Democratic president, Bill Clinton, should be impeached because he obstructed justice while former special prosecutor Kenneth Starr looked into that sexual relationship with the White House intern. Oh, and he committed perjury while talking to a federal grand jury.

Two strikes against Clinton were enough for the GOP to launch an impeachment proceeding against a Democratic president. The impeachment succeeded, but then the Senate trial produced an acquittal on all the counts.

Therein lies the conundrum that House Speaker Nancy Pelosi is facing. The House has the goods to impeach Donald Trump. Mueller’s report cited at least 10 instances where the president sought to obstruct justice. He said it again in testimony before two congressional committees in July. Why didn’t he file a formal complaint? Mueller said the Office of Legal Counsel policy prohibits him from indicting a “sitting president.”

I happen to stand with Pelosi’s decision to go slow on impeachment. She doesn’t want to proceed with impeaching Trump if there is no appetite among Republicans in the Senate to convict him of a complaint brought to them by the House.

I say all this, though, while scratching my noggin. If obstructing justice was enough to impeach a president 21 years ago, why is this instance so radically different that congressional Republicans cannot do so again now?

I think I know the answer. Congressional Republicans are playing politics with a growing constitutional crisis.