Here are the impeachment-related stories Grassfire is tracking for Tuesday, December 17:

Live: House committee debates Trump impeachment vote guidelines

CNN Poll: Support for Impeachment Dropping, Even Among Democrats

Trump tells Pelosi in blistering letter that Dems are 'declaring open war on American Democracy'

President Trump's six-page letter to Speaker Pelosi (PDF)

"You Have Found NOTHING!": Trump Warns Dems They're Playing 'Dangerous Game'

Report: Democrats Have the Votes to Impeach President Trump

McConnell rips Schumer impeachment demands, vows not to pursue ‘fishing expedition’

McConnell: Senate Won't Help 'Sloppy Schiff's' Case, May Dismiss Impeachment After Opening Arguments

Could Dems defect in Trump impeachment trial? McConnell sees opening

Bill Bennett: Schumer senses impeachment case is weak

Rep. Collins: Americans will soon see how 'pathetically weak' Dems' impeachment case is

Former fed prosecutor: Why Senate should dismiss the impeachment case