A couple of hundred ordinary Republican delegates begin to agree (6)
I believe the answer is:
accord
'agree' is the definition.
(according is a kind of agreeing)
'a couple of hundred ordinary republican delegates begin' is the wordplay.
'couple of hundred' becomes 'cc' (roman numerals).
'begin' says to take the initial letters.
The first letters of 'ordinary republican delegates' is 'ord'.
'a'+'cc'+'ord'='ACCORD'
'to' is the link.
(Other definitions for accord that I've seen before include "Agreement - conformity" , "Official treaty" , "Harmony and fellowship" , "Agree" , "'Agreement, treaty (6)'" .)