Republicans on the House Homeland Security Committee have postponed work on the fiscal 2007 Homeland Security Department authorization bill, prompting heated criticism from Democrats who say the move might undermine the committee's credibility and prevent the measure from being completed this year. According to a committee aide, Republican committee leaders say the delay is temporary while they work to pass a maritime security bill. All 15 Democrats on the panel fired off a letter Thursday to Homeland Security Chairman Rep. Peter King, R-N.Y., opposing the move. The committee did the first-ever authorization bill for Homeland Security last year, which overwhelmingly passed out of the House by a 424-4 vote.