He must be confusing "fundamentals" with "fundamentalist" because he seems to define it as a measure of the character of the American worker.  If the fundamentals of the economy meant that, however, there would only be 2 explanations for the current state of affairs: a: the american worker has always been a person of character, so the fundamentals are therefor ALWAYS strong, or b: the american worker recently went really bad - started rotting from the core.

Now I don't think that either of those scenarios define the problems with the economy these days, so I will argue that when people say the phrase :the fundamentals of the economy are strong", they are using the word "fundamentals" to mean something more along the lines of transparent, solvent, and trustworthy.  I personally feel it is dangerous for a president of the united states to believe otherwise.