Exchange rates fluctuate minute-by- minute - depending on global markets. There are many factors that influence currency rates. A lower value Euro against the dollar will simply make european imports into america more expensive.
The dollar usually rises against the euro whenever there is good news that is likely to increase confidence in the USA economy. A strong jobs report and currency reserves will also make the dollar bullish.
Not only will the America fail, but the whole economy will. If only the government listened to people more that themselves... The world will will be based on trading and of course, money will be worthless.