This from Bush is what's likely to block Congress (10)
I believe the answer is:
gooseberry
'this from bush is what's likely to block congress' is the definition.
The definition suggests a singular noun which matches the answer.
'this from bush is' is the wordplay.
I cannot quite understand how this works, but
'from' could be 'o' (I've seen this in other clues) and 'o' is present in the answer.
'is' could be 'be' and 'be' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for gooseberry that I've seen before include "it bears fruit" , "Fruit - unwanted third person" , "Third-party" , "One unwelcome near passion" , "Some intruders play it" .)