It does, because it stopped him from running for president in 1988:

In September 1987, however, reports emerged that he had plagiarized a speech by the British Leader of the Opposition and Labour Party Leader, Neil Kinnock. Other allegations of past law school plagiarism and exaggerating his academic record soon followed and Biden withdrew from the race later that month.

In this instance, because he was accused of plagiarism, or cheating, or lying, or whatever you want to call it - he did not have the opportunity to become president. Because he copied other people's speeches and those speeches had documented authors, people were able to call him on his bullshit in a public forum and prevent his run.