Right-wing politicians were mostly in favour of laissez-faire economic policies, that consisted on free functioning of the markets with minimum goverment intervention. Markets alone, would produce the most efficent outcomes, according to their viewpoint.
On the other hand, the New Deal was based on Keynesian economics that identified, as the major cause of the Great Depression, the extremely low aggregate demand figures. The solution proposed was to boost demand figures by directing large sums of public money to the creation of job positions for the large unemployed sectors, so that they can start to earn a salary and to demand products again.
Therefore, the Keynesian solution involved very intense goverment interventionism in the economy, which was highly critized by right-wing sectors. Moreover, critics stated that those large public expenditures would cause a terrible national budget deficit.