At Tuesday nights Democratic presidential debate , Sen. Amy Klobuchar and Sen. Elizabeth Warren got into a heated exchange over the best way to tax the wealthiest Americans.

This exchange was tense but fairly mundane a Democratic moderate going after a progressive who is leading in the polls. And it wasnt the first time that Klobuchar had gone on the attack against Warren during the night. Earlier, Klobuchar referred to the Medicare for All plan that Warren supports as a pipe dream.