I wrote this article on internal linking, with examples and tips, back in September 2015.
I ve since linked to it using that exact anchor text and variations on it on at least 10 occasions.
For common, high traffic terms world leader s names, celebrities etc would be used regularly in articles.
The chart below shows its rankings for David Cameron over a six month period.
In the examples above, the pages targeted with internal links all contain the keywords used in the anchor text.
It would be good to see other tests to back up this with more evidence.