[Fido969]

Last week, he said the U.S. should issue debt with a maturity of up to 100 years to lock in low borrowing costs,

Who would buy it, other than low-cap mutual funds and brokerage houses, who'd pawn it off on their clients?

[Alberta's Child]

They might be attractive to foreign investors looking for protection of value against their own currencies.

[Disestablishmentarian]

I see a 21st century Plaza Accord on the horizon, sharply devaluing USD vs. Yuan Renminbi (China) and other currencies.

This was done to Japan in the 1980s. At that time, they were the same as China today, manipulating Yen to take American industry. In 1985 Japan had 6 of 10 largest banks in the world.

Same deal. Threat of trade war (along with other serious pressures) are required to get China to go along.

The benefits will include dramatic growth in U.S. and ability to pay down the $20 trillion with cheaper dollars.