Paul Krugman states what the vital American issue is:
The question is what happens if investors change their minds — if they decide that we’re an unserious country in which the governing party believes in voodoo economics and the president is an authoritarian ruler who spends much of his time rage-tweeting about popular musicians.
And what may happen:
Right now I’m worried that the U.S. might be facing an emerging-market-type crisis: A “sudden stop,” an abrupt cutoff of inflows of foreign capital. If we have a crisis like that it could, in particular, cause a severe housing crash.
And reminds us of something called Dornbusch's law:
"The crisis takes a much longer time coming than you think, and then it happens much faster than you could have thought."