Either demand side or supply will work depending on the economy. In late 2008 and 2009, business was not about to expand. Business was bad and prospects were worse. The economic stimulus did just about what the economist were predicting. It stabilized the economy but was not enough to generate robust growth.
IMHO, the economy is ready to move now, it just needs the right stimulus to get things going. Unfortunately, we've shot all our bullets, we have cut payroll taxes, provided massive jobs programs, and cut interest rates to zero. There are only a few option available. I think the best bet would be a 50 billion dollar spending cut coupled with a 40 billion dollar cut in corporate taxes and 10 billion cut for small business. Also, elimination of some tax loopholes that are encouraging investment abroad and out sourcing jobs.