Welcome associated with Republican party (4)
I believe the answer is:
rave
'party' is the definition.
(thesaurus)
'welcome associated with republican' is the wordplay.
'welcome' becomes 'ave' (I've seen this before).
'associated with' says to put letters next to each other.
'republican' becomes 'r' (abbreviation).
'ave' put after 'r' is 'RAVE'.
(Other definitions for rave that I've seen before include "Wild party; go mad" , "modern dance music" , "Talk wildly and irrationally" , "Lively party" , "Pop dance party" .)