Over 1/2 of US employment is in firms with at least 500 employees, and 2/3 is in firms with at least 100 employees. Is this what politicians are referring to when they refer to "small business" being the "engine of American employment?" Of course, some big businesses were once small businesses, but I have a hunch that most employment growth is also in big business; the big companies are the ones that stick around, while it's the little guys that have such a failure rate. And, in fact, US employment has only become more concentrated in large employers over the past decade.
So perhaps political rhetoric, and policy, should match with reality. Big business is where the jobs are.