In the 1943 case of Colgate-Palmolive-Peet Co. v. United States, the U.S Supreme Court ruled in favor of the government, upholding a lower court's decision that Colgate had violated antitrust laws by engaging in price-fixing activities. The company was accused of setting minimum retail prices for its products and refusing to deal with retailers who sold below these prices - a practice known as resale price maintenance (RPM). In its defense, Colgate argued that it merely suggested retail prices and did not enforce them through agreements or contracts with retailers; thus, it should be exempt from antitrust scrutiny under the Sherman Act because no unlawful agreement existed between itself and any retailer. However, this argument was rejected by the court which held that even without explicit agreements or contracts enforcing RPM policies could still constitute an illegal restraint on trade if they were part of a larger scheme to fix prices.

In the dissenting opinion for the Colgate-Palmolive-Peet Co. v. United States case, it was argued that the majority's decision to uphold a conviction against Colgate-Palmolive under Section 3 of the Clayton Act was incorrect because there wasn't sufficient evidence to prove that they had engaged in price discrimination with intent to lessen competition or create monopoly. The dissent pointed out that while some customers did receive discounts, these were given due to differences in grade and quality of goods sold or cost differentials related to transportation and other factors - not as an attempt at monopolization. Furthermore, it was noted that even if such discounts could be construed as discriminatory pricing practices, there still needed proof showing this led directly towards lessening competition or creating monopoly which wasn’t provided by government’s side.