When Facebook users learned last spring that the company had compromised their privacy in its rush to expand, allowing access to the personal information of tens of millions of people to a political data firm linked to President Trump, Facebook sought to deflect blame and mask the extent of the problem.

And when that failed — as the company’s stock price plummeted and sparked a consumer backlash — Facebook went on the attack.

While Mr. Zuckerberg conducted a public apology tour in the last year, Ms. Sandberg has overseen an aggressive lobbying campaign to combat Facebook’s critics, shift public anger toward rival companies and ward off damaging regulation. Facebook employed a Republican opposition-research firm to discredit activist protesters, in part by linking them to the liberal financier George Soros. It also tapped its business relationships, persuading a Jewish civil rights group to cast some criticism of the company as anti-Semitic.

In Washington, allies of Facebook, including Senator Chuck Schumer, the Democratic Senate leader, intervened on its behalf. And Ms. Sandberg wooed or cajoled hostile lawmakers, while trying to dispel Facebook’s reputation as a bastion of Bay Area liberalism.