Something people should look at is, what will the people so with the money they get to keep? Give a 15% tax cut to a guy who makes $25,000 a year, and he's going to say "Thank god, I'm going to take this $250 and buy me more food so I don't starve." Right?
Give a 5% tax cut to the guy who makes $1,000,000 a year and what's he going to do? He'll take that $8,000 and spend it and invest it creating jobs and wealth for everyone. Which situation is helping society more?
The Left usually oppose tax cuts and advocate higher taxes for the rich because they are convinced that "the rich get richer while the poor get poorer". But this is a typical mantra- and a total lie. In 1980, if someone earned $55,000 ($75,000 today) he was in the top 5% of earners. But today the top 5% earners make over $155,000. This means a lot of people who were middle or lower class moved up. Another thing we can look at is in 1980 there were 600,000 families worth over $1 million... today that number is about 5 million families.
The most impressive aspect about this was the wealth was self-created. Before people mainly got rich by choosing their parents carefully, but not in America today- about 80% of millionaires are entirely self-made. My point is that a capitalistic system expands opportunity and went from creating the first middle class in the world to first mass affluent class in the world, a spectacular achievement.