After a grimace and eye roll, it was crystal clear where Sen. Elizabeth Warren (D-Mass.) was headed Thursday when she was challenged on her support for a wealth tax .

Warren is proposing an annual 2-cent tax on every dollar over $50 million of a familys net worth. Billionaires would pay a 6% tax above $1 billion.

There is no evidence that anyone is going to leave this country because of a 2-cent wealth tax, an exasperated Warren responded when CNBC host Sara Eisen raised the argument. Several nations have far higher tax rates, in addition to wealth taxes, so its not clear where they would go.

How about a counter-argument thats based on fact? the senator snapped.