Ecevit, one of the most senior Turkish politicians, was unable to secure the necessary support from the parties represented in the Parliament in order to form his government.
Ecevit has been a politician for a long time.
He's one of the most senior politicians, so therefore he must have been a politician for a long time. It's difficult because I don't think the system understands what seniority means in this context.
( z1 have-org-role :ARG0 ( z2 person :name ( z3 name :op "Ecevit" ) ) :ARG2 ( z4 politician ) :ARG1-of ( z5 long ) )