Yours is a false assumption.
First off, you speak as if the Middle-Class doesn't care about the nation's deficit. Fact is WE DO! WE care a great deal about it because WE make up the bulk of the "labor force". As such, WE will be that demographic group who works to pay down the deficit over the course of the next generation or two.
Second, you assume that the bulk of the Middle-Class has their hand out to the government and have some vendetta against the Wealth-Class. Nothing could be further from the truth! Middle-Class Americans as a whole don't hate the wealthy. However, we do see that there is an income disparity between the Wealth-Class and the Middle-Class which has been widely publizied. Only those who ignore this fact will discredit it as untrue.
The issue isn't whether or not one economic group has specific expectations of another, i.e., "the rich will pay the bills". The issue is "national affordability", i.e., can this nation afford to continue in its current economic policies that favor the Wealth-Class over all others where or politicians and many of our nation's citizens realize that said policies are not economically sustainable. Sure, our government spends too much. The current Administration agrees! Unfortunately, the pundits have done a masterful job of convincing the public that the needless, wasteful spending continues under a Democrat president when there has been evidence to the contrary.