[Ouderkirk]

The CNN-appointed 5th estate column "expert" on foreign affairs

Fixed it.

[forty_years]

"fifth estate" is commonly used and is grammatically correct in this context.

[Peter Libra]

FWIW.On the 5th column.

Roughly quoting:

"I have four columns marching on Madrid. I have a fifth column within."

General Emilio Mola (Spanish Nationalist in the Spanish Civil War 1936). Refering to his supporters within the city. ready to wreak havoc on the defenders. He was Franco's man and close to the fascists.