Perhaps you are referring to Romans 13?
 
Its obvious that Romans the letter has been heavily edited, 
and composed of several earlier letters. 
 
Chapter 13 is very suspect, 
and I would suggest was either:
 
(1) Added by despots like Constantine etc. to force a certain brand of 
"Roman Law abiding" Christianity upon Christians generally, or 
 
(2) Placed by Paul as a smokescreen to protect a vulnerable underground movement 
from accusations of subversion and/or treason.
 
But that is what most scholars also have said time and time again.
 
I have a book here on the textual history of Romans and its quite an eye-opener. And its a very conservative book, not any kind of 
'radical criticism' of Romans.
 
Similarly, 1st Corinthians is really 2nd Corinthians, 
and is actually a composite of several letters by Paul.
2nd Corinthians would actually be 3rd or 4th Corinthians, 
if you're counting.