There is merit to both fiscally conservative and fiscally liberal economic policies, and there is relatively equal research to suggest that both schools of thought can create a strong middle class, and decrease poverty. Everyone has their own opinion, and it is really difficult to say one perspective is entirely wrong, or that one is entirely right.
Fiscal conservatives seek to to maximize economic and job opportunities in the private sector, thus gradually weaning the need for government aid. Its merits are mostly seen in the long-term - perhaps even only a generation later, because economic recovery takes time - going along with the "Invisible Hand" of the economy. Some economists view this approach as being the most "fiscally sound" over the long-term, since very little liabilities/debt are taken on, and because of less artificial interventions into the economy, there is less risk and uncertainty for businesses during recessions, which tends to be positively correlated to hiring. But obviously, because it relies on natural economic recovery without intervention, it often creates difficulties for the poor in the short-term (as well as businesses). There really isn't any easy answers.
My purpose isn't to debate this here, but only that it isn't accurate to deem one approach as "pro-poor" and the other as "anti-poor."