With the midterm elections fast approaching, Facebook Chief Operating Officer Sheryl Sandberg will attempt to convince Congress that the social network takes the matter of election interference seriously and is taking steps to prevent it.

In testimony released ahead of her appearance Wednesday before the Senate Intelligence Committee, Sandberg detailed all the ways Facebook is working proactively to identify and remove fake accounts, prevent coordinated efforts to spread misinformation and bring transparency to political advertising.

“The threats we face are not new. America has always confronted attacks from opponents who wish to undermine our democracy,” Sandberg said her prepared remarks (read them here). “What is new is the tactics they use. That means it’s going to take everyone — including industry, governments and experts from  civil society — working together to stay ahead.”

Sandberg talked about Facebook’s efforts to detect and stop foreign election interference, through a doubling of the number of people working on safety and security and improving machine learning technology. She suggested these efforts are yielding results. The company has disabled 1.27 million fake accounts from October through March, and in August it removed more than 650 pages and accounts that originated in Iran.

“We know we can’t stop interference by ourselves,” Sandberg said. “We don’t have the investigative tools that the government has, and we can’t always attribute attacks or identify motives. But we will continue to work closely with law enforcement around the world and do everything we can to stop foreign election interference.”

The stakes are high for Facebook, whose reputation and stock has been battered by disclosures about Russian manipulation during the 2016 presidential election and the subsequent Cambridge Analytica privacy scandal. She may also, in no small part, be looking to rebuild her own stature, after drawing criticism for the company’s slow response to the mounting outrage over the political consulting firm’s hoovering of millions of users’ private data.

Twitter CEO Jack Dorsey will put in two Congressional appearances Wednesday — one, before the Senate Intelligence Committee and another before the House Committee on Energy and Commerce. He’ll need to address, head on, charges of anti-conservative bias emanating from the White House.

“Let me be clear about one important and foundational fact: Twitter does not use political ideology to make any decisions, whether related to ranking content on our service or how we enforce our rules,” Dorsey said in his prepared testimony (found here). “We strongly believe in being impartial, and we strive to enforce our rules impartially. We do not ‘shadow ban’ anyone based on political ideology.”

Dorsey notes that Twitter plays an important role in the nation’s democracy, with all 100 Senators, 50 governors and nearly every member of the House of Representatives using the platform as a conduit to reach constituents. And he emphasizes that Conservative voices are well represented on Twitter, with some 59.5 million tweets using Trump’s favorite campaign promise to “Make America Great Again.” Indeed, it was the third most tweeted hash tag of 2017.

The executive acknowledged that in July some accounts weren’t being automatically suggested when people used Twitter’s search function — a glitch Dorsey said was promptly resolved within 24 hours. The hiccup, which Dorsey said had nothing to do with politics “at all” — nonetheless prompted Trump to rail against what he called a “shadow ban” of prominent conservatives.

Dorsey goes on to detail, at considerable length, how Twitter’s algorithms work, what the company is doing to prevent election interference and provide an update on recent malicious activity on the platform.

Perhaps the biggest criticism from tomorrow’s Congressional hearings may be reserved for Google, which declined the Senate Intelligence Committee’s request to send Alphabet CEO Larry Page or Google CEO Sundar Pichai.

Senator Mark Warner, the top Democrat on the Intelligence Committee, said in a tweet Tuesday that Dorsey and Sandberg will testify and “Larry Page should be there, too. It’s not too late for @Google to step up.”

Google instead submitted written testimony from Kent Walker, the head of global affairs, who seemed to suggest that it was less vulnerable to manipulation during the election cycle.

“We identified limited activity and we took swift action, disabling any accounts we found,” Walker said in his prepared remarks. “We have continued our efforts and work diligently to identify and remove actors from our products who mislead others regarding their identity.”