It looks like things may be getting even uglier than usual over in the .

The panel now headed by Rep. Darrell Issa, a California Republican, has long been a place to watch partisan tempers fly.

But the assertion by the panel's top Democrat, Rep. Elijah Cummings of Maryland, that the investigation into the Internal Revenue Service's targeting of conservative groups should be closed appears to have only escalated the bad feelings that already existed.

Cummings called for an end to the probe after disclosing on CNN Sunday that a self-described conservative Republican manager at the Internal Revenue Service in Cincinnati — where the targeting occurred — told committee investigators that he played a key role in the decision to give conservative groups greater scrutiny. The manager also said he was unaware of and rather doubted any direction came from the White House.

The Cincinnati manager's information would appear to put a serious dent in GOP allegations that the targeting was an attempt by White House and other administration officials to hurt President Obama's political enemies.

But one thing it definitely hasn't seriously disrupted is the level of animus the parties display to each other. Both Issa and Cummings accuse each other of having less-than-honorable motives.

Here are choice bits from both Cummings and Issa.

From a letter Cummings wrote Issa that's dated Sunday:

"Over the past three years as Chairman, you have made a series of unsubstantiated allegations against the President, the White House, and senior Administration officials with little or no evidence to support your claims. Despite repeated urgings to focus on gathering facts in a bipartisan manner, you have made more and more extreme accusations with less and less evidence ...

"... Your actions over the past three years do not reflect a responsible, bipartisan approach to investigations and the Committee's credibility has been damaged as a result..."

Part of Issa's response:

"I strongly disagree with Ranking Member Cummings' assertion that we know everything we need to know about inappropriate targeting of Tea Party groups by the IRS and the case is, in his word, 'solved.' His extreme and reckless assertions are a signal that his true motivation is stopping needed Congressional oversight and he has no genuine interest in working, on a bipartisan basis, to expose the full truth ..."

This is clearly one knock-down, drag-out fight that could use a good referee.

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