GOP success in '94 can be attributed to geography more than anything else. The party just cleaned up in the South. Well, for Democrats, if they simply started winning the congressional seats in the Northeast that their presidential candidates have carried in the last four elections, they'd be awfully close to getting the 15 seats needed for control.
No seat better exemplifies the Democrats' Northeast opportunities and difficulties than the one held by Rep. Rob Simmons (R). He's very good at voting in the interest of his district over his party. But is his party ID just too much of a problem for left-leaning, Pepperidge Farm, independent voters? Democrats' chances of holding a congressional majority in '08 are dependent on the party winning a lion's share of these Northeastern targets in '06. If Democrats don't pull many of these but still get the majority, it actually puts them in more peril in '08. (Todd)
Todd has a good point about geography and 1994. The Southern Democrats who lost in 1994 were all leftovers, remnants from the Civil War era. So, too, are many of the Northeast's Republicans.
The problem, of course, is that America runs the risk of becoming so geographically segregated that we become, in essence, two different one-party states bound together by a gridlocked federal government. That, we don't need.
Todd, Chuck. "So You Want To Be A Pundit? Study These Eight Races." NationalJournal.com 26 October, 2006.