On Thursday’s broadcast of MSNBC’s “All In,” Sen. Richard Blumenthal (D-CT) said his colleague Sen. Lindsey Graham (R-SC) would end up regretting investigating 2020 presidential hopeful former Vice President Joe Biden.

Blumenthal said, “I really regret that he has launched on this course. I think he’ll regret it too, because not only is it completely spurious, he knows it’s been debunked, it’s also, in fact, relying on this, insane as you have correctly called it, conspiracy theory involving Ukraine. It endangers our national security. This Ukrainian theory is one of the central tenets and tropes of Russian propaganda and disinformation.”

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