[Grammar] Why there’s no article?

[northpath]

I quote that text from the Macmillan dictionary online, topic phrasl verbs 'set up':
MAINLY BRITISH to put someone in a position of power
set someone up as something: a plan to set him up as party leader.
Why there’s no article before the word ‘party’. I would put the indefinite article: a plan to set him up as a party leader.

 

[Charlie Bernstein]

Why is there no article?

I quote this text from the Macmillan dictionary online, topic phrasal verbs 'set up':

MAINLY BRITISH to put someone in a position of power
set someone up as something: a plan to set him up as party leader.

Why is there no article before the word ‘party’? I would use the indefinite article: a plan to set him up as a party leader.

You would be changing the meaning of the phrase. They're not setting him up as one of several leaders. They're setting up the single number-one leader. So if there were an article, it would be the, not a.

But the is understood, so there's no need to say it.

Notice how you wrote "topic" instead of "the topic"? It's the same thing. Saying "a topic" would make no sense, right? So when you say "topic," we understand that you mean "the topic."

 

[bubbha]

Often with titles, we don't use "the".

"As professor of English at Harvard University, I am proud to announce..."
"Ms. Anderson was chosen to serve as project manager after her predecessor suddenly quit."