Feeling terrible tension's gripping America (9)
I believe the answer is:
sensation
'feeling' is the definition.
(sensation is a kind of feeling)
'terrible tension's gripping america' is the wordplay.
'terrible' is an anagram indicator.
'gripping' indicates putting letters inside (inserted letters are gripped).
'america' becomes 'a' (common abbreviation - e.g. in organisation names).
'tensions' anagrammed gives 'senstion'.
'senstion' placed around 'a' is 'SENSATION'.
(Other definitions for sensation that I've seen before include "Feeling, awareness of stimulation" , "Feeling; thrilling person or thing" , "Physical feeling or perception" , "Awareness of a stimulus, such as heat or pain" , "Scandalous news item" .)