(Bloomberg) -- Antitrust enforcers should be willing to challenge mergers that decrease competition, without trusting corporations to stick to promised remedies, a top Justice Department official said Thursday, two days after the department sued Alphabet Inc.’s Google to break up its online advertising business. 

Doha Mekki, the principal deputy assistant attorney general in the department’s antitrust division, said agencies under previous administrations have “usurped the will of Congress” by declining to enforce the letter of antitrust laws that are in some cases more than century old. 

She called for the government to operate with a “bias towards action,” even if it means occasionally losing in court. 

Mekki’s comments came after the Justice Department on Tuesday filed the landmark case against Google over its dominance in online advertising. She said the case highlighting the government’s missed opportunities to protect competition in emerging industries such as online advertising. 

Google, in response to Tuesday’s lawsuit, said the Justice Department “is doubling down on a flawed argument.”

During a speech at George Mason University in Virginia, Mekki said “our reliance on predictions have failed us.” The university is known for a free-market approach to antitrust and some of its professors have at times criticized the Biden administration’s aggressive antitrust enforcement.

She referred to the Federal Trade Commission’s decision to sign off on Google’s acquisition of advertising technology platform DoubleClick Inc. during the George W. Bush administration. 

At the time, several FTC commissioners acknowledged that the acquisition could enable Google to dominate the online advertising ecosystem, but they chose not to block the deal because they could not adequately predict what the market would look like years down the line.

“That acquisition was a turning point,” Mekki said. “As we alleged in our complaint, it vaulted Google into a commanding position over the tools online publishers use.” 

She said the FTC commissioners’ statements at the time “read as a roadmap” of the conduct that Google would later engage in, but they failed to intervene. Now, Google’s acquisition of DoubleClick plays a central role in the DOJ’s case against Google. The DOJ’s complaint filed Tuesday seeks to force Google to spin off its online advertising division. 

Mekki said government enforcers should focus on enforcing the law as Congress intended — with a focus on what markets could become rather than only what they look like today.

“Focus on measuring competition, rather than predicting the competitive effects with certainty in a dynamic world,” Mekki said. “That is the more consistent framework under the statute that Congress wrote.”

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