Washington (CNN) – One of the hottest political feuds in Washington ratcheted up another tense notch Friday as House Oversight Committee Chairman Darrell Issa, a California Republican, accused Democratic Rep. Elijah Cummings of undermining an investigation into why the IRS targeted conservative groups.
Cummings fired back, calling Issa’s behavior “abusive.”
First, Issa: “You have made yourself an obstacle to effective congressional oversight,” he wrote Cummings in a sharply worded four-page letter Friday.
It went on to accuse Cummings, the top Democrat on his committee, of operating, “in effect (as) a defense counsel for (former IRS employee) Lois Lerner.”
Quickly responding, Cummings’ office called the letter “offensive” and Issa’s actions in a hearing last week “abusive.”
The barbed words are the latest in a back-and-forth-and-back-again fight between the two men over whether Issa can charge Lerner with contempt of Congress.
For over a year, Lerner has refused to testify publicly about her role in IRS targeting of tea party groups, citing her Fifth Amendment protection from self-incrimination.
The issue exploded at a hearing last week when Lerner again refused to testify.
After Cummings tried to make a statement and ask a question, Issa had the Democrat’s microphone turned off. That sparked a waterfall of outrage from Democrats and an apology from Issa.
Cummings next wrote two letters to House Speaker John Boehner, an Ohio Republican, arguing that Issa’s behavior blocked the possibility of contempt charges.
The Democrat cited two former congressional attorneys who believe that Issa neglected to clearly overrule Lerner’s Fifth Amendment assertion or tell her that she must answer the committee’s questions. Therefore, they argue, Issa cannot file for contempt.
Friday, Issa fired back in his letter to the Maryland Democrat.
“You and your lawyers and consultants are wrong on the facts and the law,” Issa wrote.
Issa cited the committee’s resolution rejecting Lerner’s Fifth Amendment privilege and argued that Supreme Court case law supports his position. Issa then said Cummings was blocking the investigation.
In a sign of the deteriorating discourse, the Oversight chairman needled his Democratic counterpart about how he obtained his position.
“Even though the White House helped orchestrate your ascension to ranking member,” Issa wrote to Cummings, “I … continue to encourage … you to subordinate your political loyalties to the institutional interests of the Committee and the House.”
In response, an aide working for Cummings on the Democratic side of the Oversight panel shot back:
“Frankly, it’s offensive that the chairman would accuse Rep. Cummings of undermining the integrity of the committee after the entire country just witnessed his abusive actions at last week’s hearing,” the Democratic House Oversight aide told CNN.
Meantime, Issa is preparing the landscape for possible contempt charges. Tuesday he filed a 141-page report laying out a case against Lerner.