WASHINGTON (Reuters) - A hard-line Republican effort to impeach the top U.S. tax collector came under fire on Tuesday from Democrats who called it an unsubstantiated partisan attack that could undermine the credibility of Congress. Internal Revenue Service Commissioner John Koskinen faces  allegations before the House Judiciary Committee of ignoring congressional subpoenas and misleading lawmakers. The accusations stem from a 2013 scandal in which the IRS was criticized for targeting conservative Tea Party groups’ applications for tax-exempt status for extra scrutiny. Some Republicans want the Republican-controlled U.S. House of Representatives to vote on impeaching Koskinen before Congress leaves for its midyear break in July. Democrats oppose the effort.  “This resolution fails by every measure. It arises from the worst partisan instincts. It is not based in the facts,” Representative John Conyers said at the outset of the first of two Judiciary Committee hearings to examine charges against Koskinen. “When a vote for impeachment is divided on party lines ... we undermine our credibility,” added Conyers, the panel’s top Democrat. Koskinen angered critics by declining to testify, but submitted a statement saying the charges are without merit and fail to meet the constitutional impeachment standard of “treason, bribery or high crimes and misdemeanors.” In his absence, the committee heard from Republicans on the House Oversight and Government Reform Committee, which investigated the Tea Party scandal and concluded that Koskinen failed to preserve evidence that was later destroyed. “This is really a simple case in my mind. When Congress asks you a question, you’re expected to give a truthful answer. When Congress issues a subpoena, compliance is not optional,” House oversight panel Chairman Jason Chaffetz testified. Chaffetz described impeachment as the remedy Congress has for officials guilty of breaching the public trust. But Democrats noted that IRS and Federal Bureau of Investigation probes produced no evidence of criminal wrongdoing or deliberate efforts to mislead Congress. They said the case against Koskinen showed little more than agency mismanagement and misstatements. Judiciary Committee Chairman Bob Goodlatte offered no direct criticism of the impeachment push, but avoided using the term other than to name impeachment as one of several options that include “the power to write the laws, the power of the purse ... and the power to censure.”    
Republican push to impeach U.S. IRS chief hit by Democrats