European political party supporting US president? That's false (7-2)
I believe the answer is:
trumped up
'false' is the definition.
(synonyms)
'european political party supporting us president?' is the wordplay.
'european' becomes 'E' (abbreviation e.g. EU).
'political party' becomes 'DUP' (Democratic Unionist Party).
'supporting' is a charade indicator (letters next to each other) (in a down clue, some letters go below others).
'us president?' becomes 'trump' (I've seen this before).
'e'+'dup'='edup'
'edup' put after 'trump' is 'TRUMPED-UP'.
'that's' acts as a link.
(Other definitions for trumped up that I've seen before include "Falsely charged" , "Concocted, charges perhaps" , "false charges?" , "Played winning card" , "False and deliberately invented" .)