Ending the payroll tax would hit 70 million voters who receive Social Security and Medicare.
Academic researchers are now starting to sift through the data, and unpick the details of how the crisis played out on stocks and broader markets.
Market volatility is back - and investors expect more wild swings in the coming weeks and months as the U.S. presidential election closes in.
The 2020 election race between incumbent President Donald Trump and former Vice President Joe Biden is a coin toss.