The hearing's focus on Wednesday on presidential power came amid a widening probe by Special Counsel Robert Mueller into Russian meddling in the 2016 US election and turmoil within the White House, clouding the presidency of Trump, who is working to get more conservative judges appointed to the federal courts.
But the emails are among tens of thousands that have been turned over to the Judiciary Committee, though they are not yet public.
Meanwhile, Republicans pointed to the huge number of documents released, the most ever for a Supreme Court nominee, to make the case that the review of Kavanaugh is "the most thorough and transparent confirmation process in history".
"I'm not remembering, but I'm happy to be refreshed or if you want to tell me who you're thinking of", Kavanaugh said. Kavanaugh still declined to engage in a hypothetical he said closely resembled the earlier one.
Sens. Susan Collins of ME and Lisa Murkowski of Alaska, who both favor abortion access, are the only two Republicans even remotely open to voting against Kavanaugh, though neither has said she would do so.
Trump has denied any such collusion and has repeatedly called Mueller's investigation a "witch hunt."
Harris' question appeared to puzzle the Supreme Court nominee, who paused for long periods before asking the California senator if she wanted to know whether he spoke with a specific person at the firm.
The Democrats weren't the only ones who recognized the importance of questions about Trump and the Russian Federation investigation.
But in 2009, Kavanaugh wrote a law review article saying presidents should be free from the distractions of civil lawsuits, criminal prosecutions and investigations while in office.
"If we don't have at least 50 votes, I'm sure that no Democrats would dare give us the 50th vote", Grassley said on Wednesday in a press conference.
"It may not be on his preference for key lime pie over chocolate, for instance, but it is a personal belief about what the Constitution requires and what regulatory agencies can and cannot do", she said. "The independence of the judiciary is critical to the confidence of the American people".
"That takes some backbone".
During the hearing, Democrats also plan to grill Kavanaugh on the Affordable Care Act and executive power. Richard Blumenthal of CT to pledge to step aside from any Supreme Court cases dealing with Trump and Mueller's investigation.
"Respect for precedent is important. We are independent. We make decisions based on law, not based on policy, not based on political pressure, not based on the identity of the parties, no matter who you are in our system, no matter where you come from, no matter how rich you are or how poor you are, no matter your race, your gender, no matter your station in life, no matter your position in government", he added. U.S. Capitol Police quickly and sometimes roughly moved the protesters out of the room before many of them could be clearly heard. Republican, Democrat differences. But in the three-and-a-half years that I've been chairman of the committee, every bill that has come out of the Judiciary Committee has had bipartisan support.
The president's comment followed the statements of Democratic senators who warned that Trump was, in the words of Senator Richard Blumenthal of CT, "selecting a justice on the Supreme Court who potentially will cast a decisive vote in his own case".
Senate Democrats have vowed a fierce fight. One is an email drafted by Kavanaugh in 2003, in which he questioned whether the Supreme Court's 1973 Roe v. Wade decision legalizing abortion should be described as "settled law of the land".
President Donald Trump, who nominated Kavanaugh on July 9, weighed in on the ruckus on the committee as Kavanaugh read his opening statement, before the meeting wrapped up for the day.