Technically, Nixon lied that he did NOT know of the break in. He knew and admitted such later.
Of course the break in was to:
1) Prove that the DNC was laundering money for the Teamsters Union
2) That the DNC was running a prostitution ring from the office (John Dean’s future wife was running it...)
The ‘Burglars’ found the proof, hence the misdirection...
Most do not know the latter, and there is the Mike Mansfield ‘helping’ to keep LBJ’s crimes undercover...
“Nixon lied that he did NOT know of the break in.”
He didn’t know about it before it happened, only after (hence the cover-up).
The real reason is at post #21.