The Obama Justice Department developed a track record in challenging horizontal mergers and acquisitions—those in which a company buys a direct competitor—in industries that are already highly concentrated. In deals that are not between direct rivals, such as those that occur in vertical integration, the Obama Administration approved the deals, albeit with the imposition of legally binding restrictions on the acquirer’s ability to use its “in house” supplier to engage in unfair competition.
The full essay is at "A Bias in Obama's Antitrust Policy?"