Actually, additional money printing actually hurts the middle class more as most of their income is in the form of wages and their purchasing power falls as more money is printed. The rich have more of their wealth stored in money-generating assets (stocks, RE, etc).
Wage-earners don't face inflation issues if there's any sort of robust job market, as the incomes and wages naturally rise alongside inflation. Since government spending improves the job market, chances are the wages are going to rise in line with the inflation. It's those who rely on savings who are hurt much more than those who rely on wages.
The money-generating assets only help the rich if their assets are receiving adjustable-rate returns. When assets with fixed returns (fixed-rate bonds, mortgages, loans, etc.), the rich are screwed over by inflation because the bonds lose their expected return value and the debtors find it easier and easier to pay their loans off. In an economy so heavily based on debt like our own, inflation advantages debtors and disadvantages creditors.
We don't need to argue hypotheticals, just look at how the wealthy behave. The rich
hate government spending unless the spending goes directly to them. The rich
hate inflation to the point (see early 1980s Reagan Administration) where they'd actually cause a recession rather than face the risk of inflation. The rich are always heavily pressuring the government to avoid making moves that risk inflationary outcomes, while populists are typically pushing for inflationary outcomes.