>I don't know if or how this fits within actual antitrust law, but it makes sense that the issue was never price gouging, the issue was one entity gaining too much power.
In the US, there are two major areas of antitrust law and enforcement:
1) Sherman & Clayton Acts (1890, 1914) - outlaws cartels and anticompetitive activities (that is, activities that tend to lead to monopolies, but doesn't outlaw monopolies themselves). Price gouging is not an antitrust issue, but predatory pricing and price fixing are (you might have meant these terms). This area is primarily established via case law and enforced by the courts (and DOJ AD).
2) Merger guidelines/Federal Trade Commission (1968) - wherein key mergers must be reviewed and approved by the FTC. This area is more sensitive to political climate / executive branch as it's executive-appointed FTC regulators who set the guidelines and give approvals. We are now exiting an era of historic hands-off-ness.
Source: had a professor who is famous in antitrust world