I don't take it for granted that "the wealthy should be taxed at higher rates to help the poorer", as some say.
Even if the wealthy are taxed at the same rate, they are still paying more tax than the not-so-wealthy are paying.
And seeing they are wealthy, presumably it's because they are clever entrepreneurs - so why take even more money off those who are most capable of using the money to create jobs? Is the Government really going to create jobs better than the nation's most experienced business-operators?
Leaving the money in the entrepreneurs' capable hands would eventually increase the Government's revenues anyway - because the nation's wealthiest are known for using their money to create more money - and hence, pay more taxes - unlike the poor who tend to use their money for day-to-day needs rather than for creating more money.
From an ethical point of view, it's interesting that in the Law given to Israel by God through Moses, a progressive tax was never imposed on society to help the poor - it was always a flat 10% for everybody without discrimination as to industry or amount of profit. That was the pattern in God's Word - the standard of justice and compassion.
So I don't think it ought to be taken for granted that the wealthy should be taxed at higher rates to help the poor. It's certainly worth considering whether there isn't a fairer and more successful way of delivering for the poor.
Compassion isn't justice if you're unfairly using someone else's money to do it.