Blue Firewall
From dKosopedia
The Blue Firewall is a collection of eighteen states and the District of Columbia that have not voted for any Republican nominee for President since 1988. They have voted for Bill Clinton in 1992 and 1996, Al Gore in 2000, John Kerry in 2004, and Barack Obama in 2008. Random chance that this collection of states and the District of Columbia would so vote is 1 in 2^95, or one chance in a number with 29 digits. The states and the district are:
California
Connecticut
Delaware
District of Columbia
Hawaii
Illinois
Maine
Maryland
Massachusetts
Michigan
Minnesota
New Jersey
New York
Oregon
Pennsylvania
Rhode Island
Vermont
Washington
Wisconsin
In 2008, Barack Obama won every one of these states by at least 10%.
These are now difficult states for any Republican nominee for President to win. They are the states generally to the northeast of the Potomac River except for New Hampshire (which George W. Bush won in 2000 in a close election), states bordering the Great Lakes except for Indiana and Ohio, and four of five states bordering the Pacific Ocean.
These states have not always been sure wins for a Democratic nominee for President. As late as 1976, Jimmy Carter lost nine of these states in a close election that he won.