High tariffs had more or less disappeared for the last 75 years until the Trump administration brought them back. But a unique database of investment returns that dates back to 1875 shows that high tariffs can coexist with stock-market gains.

"That will work now," Sen. Thom Tillis said of Trump blaming Biden for the stock market. "It won't work six months from now."

In 100 days full of surprises for investors, the S&P 500 and Dow nearly recouped their April declines – even with a worse-than-expect GDP report.