If this is such a good thing, why is every senior Democrat in Washington in a projectile sweat trying to figure out some mechanism to stop it?

Wall Street began the second quarter with a big rally Tuesday as investors rushed back into stocks, optimistic that the worst of the credit crisis has passed and that the economy is faring better than expected.

The Dow Jones industrials surged nearly 400 points, and all the major indexes were up more than 3 percent.

Wall Street got another boost when the Institute for Supply Management said its March index of national manufacturing activity rose to a reading of 48.6 -- indicating a contraction, but a slower one than in February and tamer than many analysts had predicted.

Government data on construction spending for February also came in better than expected.

In the past decade, there has been an explosion in complex derivative instruments, such as collateralized debt obligations and credit default swaps, which were intended primarily to transfer risk.

These products are virtually hidden from investors, analysts and regulators, even though they have emerged as one of Wall Street's most outsized profit engines. They don't trade openly on public exchanges, and financial services firms disclose few details about them.

[Treasury Secretary Henry] Paulson's proposal is aimed at curbing the kinds of risky investments that led to the current credit crisis, like the widespread use of complex mortgage-backed securities.

"I have no intention of stopping until we finish what we started and until we see what happens in the next 10 contests and until we resolve Florida and Michigan. And if we don't resolve it, we'll resolve it at the convention -- that's what credentials committees are for."