With the Democratic primaries in full swing, many campaigns are making the necessary investments to attract more voters to their ranks.
Some candidates have good name recognition and others still struggle to reflect their popularity in official polls.
One could take the very pragmatic view that the media is interested in selling the “product” people want. In other words, if there is interest in one particular candidate, it is natural that such candidate will receive the most coverage. It is basic economics: Supply and demand.