Conservative guy, not too bright, seen around Republican festival (7)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

C (Conservative) + HIMBO (guy, not too bright) round R (Republican) – a jorum for me: with very little confidence, I looked up HIMBO and found ‘an attractive but empty-headed young man’ – obvious now, of course: a male bimbo I wouldn’t ever use CHRIMBO but, if I did, I wouldn’t include an h – it’s in Collins but not Chambers