The system of checks and balances works best when the separate branches of government are inherently and proudly adversarial toward one another. But that can’t happen when partisanship defines when and how accountability moments play out.

House Oversight and Government Reform Committee chairman Darrell Issa -- the headline-hungry California Republican who on Wednesday engineered a committee vote to hold Attorney General Eric Holder in contempt -- forgot that essential rule.

He failed to build a credible case or a credible coalition for his initiative. After a day of increasingly ridiculous posturing, Issa secured the contempt citation he sought. But it came on a straight party-line vote that rendered the decision all but meaningless.