You can pretend it "had nothing to do with inheriting anything", but the facts are otherwise. A "two-tiered" society is created by capitalism, an economic system based on employers (exploiters) and employees (exploitees). A democratic government is a social apparatus organized by the people to manage their large-scale socioeconomic affairs and interests. It's an institution created to serve the public good, unlike private business enterprises, whose bottom line is profits (capital accumulation). On the public accountability scale, democratic governments rank much higher than privately owned businesses due to the fact that at least democracies hold elections, maintain courts of law, and are in principle supposed to serve the interests of their citizens. When was the last time you participated in an election at work? About never?
Republicans claim to serve the working class by prioritizing the needs of the rich under the pretext that the wealthy elites will invest their wealth back into their businesses, creating opportunities for employment and upward mobility, but the reality is that the trickle-down doesn't trickle. The golden age of our economy after WW2, shortly after FDR's new deal of the 1930s (to avoid a second civil war during the great depression) was still strongly in place and the highest tax bracket was 91%. The highest-paid CEOs at the time made about 20 times the average worker, whereas today the highest-paid CEOs make an average of 350 times the average salary of their employees.
Republicans create extreme inequality and add insult to injury by disempowering the working class by making it practically impossible for them to unionize and receive the benefits and social safety net that they need to live above the poverty line. More than half of the American workforce is living paycheck to paycheck, hand to mouth, unable to spend more than $400 in an emergency. Many Americans can't afford a college or vocational school education and even if they can pay their tuition they have to work to survive, hence don't have the time or energy to study. Tens of millions of Americans are uninsured and hence never go to the doctor for a checkup, they wait until they're seriously ill, dragging themselves half-dead into an ER. That's America, thanks to Republican, trickle-down economics (prioritizing the vested interests of the rich at the great expense of the public good).
Despite of all of the flaws of the Democrats, at least they are more in tune with the needs of the public and support policies that help mitigate the destructive effects of late-stage capitalism. If it wasn't for the Democrats (the "leftists"), we wouldn't have Social Security, Medicare, Medicaid..etc.