But even if true, I guess this shows that tax cuts don't result in predictable economic outcomes (since Bush's tax cuts ended in recession). In short, you're arguing against yourself.
My longhand response would be something more like: economic growth is the result of numerous factors, many of which are not in the control of presidents. That said, progressive taxes, investment in public works, education and health care, is the surest way to avoid large income gaps that do in fact lead to recession. So while progressive economic policies might not prevent a recession, conservative policies almost insure we will have one.