President as leader of Republicans featured in article (6)
I believe the answer is:
pierce
'president' is the definition.
(Franklin Pierce, 14th US president)
'leader of republicans featured in article' is the wordplay.
'leader of' suggests taking the first letters.
'featured in' means one lot of letters goes inside another.
'article' becomes 'piece' (piece is a kind of article).
The first letter of 'republicans' is 'r'.
'r' going inside 'piece' is 'PIERCE'.
'as' acts as a link.
(Other definitions for pierce that I've seen before include "Skewer; run through" , "Impale" , "boy?" , "force way through" , "Puncture or penetrate" .)