How many {political alignment} are to/by {populism} ?
How many have the political alignment of populism?
Populism is the political alignment of how many?
SELECT ( COUNT ( ?q ) AS ?a ) { ?q property:political_alignment resource:populism }
SELECT (COUNT(?sub) AS ?subs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?sub .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P1387> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q180490 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P1387 wd:Q180490 }
3