Their relationship has echoes of the dynamics between Senate Majority Leader Lyndon Johnson and northern liberals in the 1950s.

CNN: Don't count Boehner out in debt crisis

Conservative southern Democrats, alienated by the growing influence in their party of minorities and northern liberals, began to cast ballots for Republicans throughout the South.

ECONOMIST: Democrats in Texas

Moreover, this new majority, if it emerges, will be much more ideologically cohesive than the Democratic majority of Bill Clinton's first two years, which was an uneasy alliance between Northern liberals and conservative Southerners.

NPR: Krugman: Income Inequality Pricks 'Conscience'