Barr is scheduled to appear before the committee on Thursday.
The “human wall” came just two days before the president was scheduled to hold a rally in El Paso Monday night.
Barr also assured the Senate Judiciary Committee that he would not fire Mueller without due cause.
The Senate officially confirmed Brett Kavanaugh as the next Supreme Court justice on Saturday.
Kavanaugh explained his angry and intense behavior during his public testimony last week in an op-ed in The Wall Street Journal.
The FBI on Wednesday wrapped up its days-long supplemental background investigation into allegations against Kavanaugh.
The White House has allowed the FBI to interview anyone it deems necessary, as long as the probe is finished by the end of the week.
Here is what you need to know about Kavanaugh and the newly reopened supplemental background investigation.
One day before their hearing, Kavanaugh and Ford have released their prepared opening statements to the Senate Judiciary Committee.