Congressman Charles Rangel, D-N.Y., is hearing more calls for him to step down from his chairmanship of the tax-writing House Ways and Means Committee after a series of embarrassing revelations.

Last month, Rangel quietly filed financial disclosure forms showing that he had failed to disclose over half a million dollars in assets in 2007. He has been subjected to a steady drumbeat of criticism ever since. The latest is an editorial in the Washington Post today decrying some of the newest revelations from last week, including a Merrill Lynch account valued between $250,000 and $500,000, tens of thousands in municipal bonds, and between $30,000 and $100,000 in rent from a Harlem brownstone that he owns, all of which he failed to list on his congressional disclosure forms from 2002 to 2006. This comes on top of the news last year about the four rent-stabilized apartments he rented at below-market rents, his use of government stationery to raise money for a pet project, his failure to report income from his sale of a Florida condo, and his failure to pay taxes on rental income from another home in the Dominican Republic.

Rangel has been a fairly effective leader of his committee in recent years, but the ethical quandary posed by his failure to report or pay taxes when he runs the most powerful tax-writing committee in the House is obviously vexing. Rangel was supposed to have hired a forensic accounting firm to sort out the mess last year (see Rangel Picks Forensic Accounting Firm). Instead, the revelations just keep snowballing. Perhaps it’s time for him to step aside and leave the tax-writing duties to someone else on his committee who keeps better records.