Look more impressive having dismissed first of Republicans (6)
I believe the answer is:
gander
'look' is the definition.
(informal term for a look or glance)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for gander that I've seen before include "Male goose; look (colloq.)" , "Butchers - goose" , "glance" , "Goose sauce is good for it" , "waterbird" .)