Earlier this week, The Rachel Maddow Show found evidence of Sen. Rand Paul (R-Ky.) lifting several sentences from a Wikipedia entry and including the lines in a speech without attribution. As most of us are taught in middle school, when someone takes others’ work and presents it as their own, it falls under the category of “plagiarism” – which in national politics, can be problematic.

Soon after, BuzzFeed found another instance in which the Republican senator presented text from a Wikipedia entry as his own original text. And then The Rachel Maddow Show found yet another instance of Rand Paul plagiarism.

Though Paul talked with several national reporters this week, none chose to ask him about these clear, documented, demonstrable examples of Paul presenting others’ work as his own. To his credit, Fusion TV’s Jorge Ramos asked the Kentucky senator to explain himself on Wednesday, and Paul offered a multi-part defense.

Paul said, for example, that when he used others’ work in describing movies without attribution, it wasn’t plagiarism because he didn’t take credit for writing the movies. Paul also said the issue relates to missing “footnotes” that he apparently considered part of his written remarks. He added that Rachel Maddow is a “hater,” which he apparently considers a relevant part of his defense.

In other words, Paul either doesn’t know what “plagiarism” means or he’s pretending not to know what “plagiarism” means. As an objective matter, it has to be one or the other.

Last night, however, Politico found even more examples of Paul presenting language from others in his speeches without attribution – at which point, the senator’s office apparently decided the “hater” defense was no longer sufficient.

A top adviser to Sen. Rand Paul said Thursday night that the Kentucky Republican would be “more cautious in presenting and attributing sources” in the future, after POLITICO confronted the senator’s office with fresh examples of Paul speeches that borrowed language from news reports without citing the original text. POLITICO contacted Paul’s staff Thursday evening with multiple instances in which the popular conservative used language – either word-for-word or nearly verbatim – that had first appeared elsewhere.

In this case, Politico found instances in which Paul lifted text from an Associated Press article and an article published in a Focus on the Family magazine. Neither was credited in the senator’s remarks.

Presented with five documented instances in which Paul’s speeches featured others’ work, Paul adviser Doug Stafford complained about “liberal media angst” – I’m not sure what that means in his context – before saying the senator will “be more cautious in presenting and attributing sources” in the future.

The funny thing is that if Paul and his team simply acknowledged the error, blamed sloppy staff work, and pledged to be “more cautious” going forward, the story probably would have faded rather quickly. But instead, the Kentucky Republican, despite being caught clearly presenting others’ work as his own, tried to redefine “plagiarism” and rely on name-calling as a way to justify his misdeeds. These are the kind of actions that would get a high school student into fairly serious trouble, but which a U.S. senator apparently feels entitled to.