The independent expenditure arm of the National Republican Congressional Committee launched 16 new ads Friday backed by a combined total of more than $6 million.

Republicans are poised to comfortably keep control of the House, but how much the chamber’s margin shifts will largely depend on the way competitive races swing over the next 23 days.

The NRCC is on television — playing both offense and defense — in the following districts:

• This spot in California’s 7th district, backed by $560,000 in the Sacramento media market for a week, attacking physician Ami Bera (D), who is taking on Rep. Dan Lungren (R)
• This spot in California’s 9th district, backed by $560,000 in the Sacramento media market for a week, attacking Rep. Jerry McNerney (D), who faces recent law school graduate Ricky Gill (R)
• This spot in California’s 24th district, backed by $115,000 in the Santa Barbara media market for a week, attacking Rep. Lois Capps (D), who faces former Lt. Gov. Abel Maldonado (R)
• This spot in California’s 52nd district, backed by $400,000 in the Santa Diego media market for a week, attacking San Diego Port Commissioner Scott Peters, who is taking on Rep. Brian Bilbray (R)
• This spot in Colorado’s 6th district, backed by $560,000 in the Denver media market for a week, attacking state Rep. Joe Miklosi (D), who is taking on Rep. Mike Coffman (R)
• This spot in Georgia’s 12th district, backed by a combined total of $192,000 in the Savannah and Augusta media markets for a week, attacking Rep. John Barrow (D), who faces state Rep. Lee Anderson (R)
• This spot in Illinois’ 11th district, backed by $900,000 in the Chicago media market over two weeks, attacking former Rep. Bill Foster (D), who is taking on Rep. Judy Biggert (R)
• This spot in Michigan’s 1st district, backed by combined total of $144,000 in the Marquette and Traverse City media markets for a week, attacking former state Rep. Gary McDowell (D), who is taking on freshman Rep. Dan Benishek (R)
• This spot in Minnesota’s 8th district, backed $426,000 in the Minneapolis media market over two weeks, attacking former Rep. Rick Nolan (D), who is taking on freshman Rep. Chip Cravaack (R)
• This spot in Nevada’s 3rd district, backed by $426,000 in the Las Vegas media market over two weeks, attacking state Speaker John Oceguera (D), who is taking on freshman Rep. Joe Heck (R)
• This spot in New York’s 19th district, backed by $326,000 in the Albany media market over two weeks, attacking attorney Julian Schreibman (D), who is taking on freshman Rep. Chris Gibson (R)
• This spot in Ohio’s 6th district, backed by a combined total of $231,000 in the Youngstown and Wheeling, W.V. media markets for a week, attacking former Rep. Charlie Wilson (D), who is taking on freshman Rep. Bill Johnson (R)
• This spot in Ohio’s 16th district, backed by $517,000 in the Cleveland media market for a week, attacking Rep. Betty Sutton (D), who faces freshman Rep. Jim Renacci in a Member-versus-Member race
• This spot in Texas’ 23rd district, backed by $315,000 in the San Antonio media market for a week, attacking state Rep. Pete Gallego (D), who is taking on freshman Rep. Francisco “Quico” Canseco (R)
• This spot in Utah’s 4th district, backed by $250,000 in the Salt Lake City media market for a week, attacking Rep. Jim Matheson (D), who faces Saratoga Springs Mayor Mia Love
• This spot in Wisconsin’s 7th district, backed a combined total of $550,000 in the Minneapolis, Minn., and Wausau, Wis., media markets, attacking former state Senate President Pro Tem Pat Kreitlow (D), who is taking on freshman Rep. Sean Duffy