I'll make Trump shaken up when I choose to cross over (7,7)
I believe the answer is:
whoopee cushion
'cross over' is the definition.
The definition suggests a singular noun which matches the answer.
'i'll make trump shaken up when i choose' is the wordplay.
I cannot quite see how this works, but
'make' could be 'pee' (synonyms) and 'pee' is found within the answer.
'when' could be 'on' (I've seen this in other clues) and 'on' is found within the answer.
'i' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
'to' acts as a link.
Can you help me to learn more?
(Other definitions for whoopee cushion that I've seen before include "Inflatable source of much mirth?" , "source of juvenile amusement" .)