Technically it could.
There is no "technically" about it. It is an empirical fact that it most certainly does. It is why Ronald Reagan raised taxes six times. Because he was trying to offset the effects of his massive deficits.
But it doesn't reduce ineffective spending
Which is another issue altogether.
(and we've already demonstrated that Democratically controlled Congresses spend much much more than Republican led ones).
Too bad facts run contrary to this assertion. American alone spends twice as much on its military than the next two countries combined. And what do we have to show for it? Nothing. We are no more "secure" than Canada, Brazil, Argentina, Germany, etc. And it should go without saying that our ridiculous spending on military and overseas wars is overwhelmingly driven by Republican agendas.
However, even a rich person's money sitting in the bank is helping the economy because it can be borrowed against for things like capital investment.
So now your'e moving the goal posts again, going away from the issue of deficit, to the issue of economic positives. Of course it is always a positive to have wealth that can be borrowed, but the fact is our tax dollars gave billions to banks who were supposed to turn around and loan that money out, but instead they just sat on it because the Republicans in the Treasury dept rushed it throughh without any stipulations as to how that money had to be spent. Only after Obama was elected did he trying to enforce measures that would ensure that money would find its way back into the economy, but when he did that, you all attacked him for being a socialist! But the fact is stimulus spending, giving tax breaks to the lower classes, is much better for the economy because that money goes right back into the economy almost immediately. Lower/Middle-class folks aren't in a position to just sit on their money like the wealthy are. If they have it, they're most likely to spend it on things that really make the economy churn.
And since over-taxation and deficits are a huge drag on the economy
Over-taxation meaning....? At what point is taxation "over-taxation"? The wealthy are now enjoying record lows in taxation. At what point does taxation become over-taxation? You don't say, because you can't say. And about deficits, we need to look no further than Ronald Reagan to thank for that recent American tradition. Remember, "deficits don't matter" was their mantra when trying to convince Americans that they needed to dump all our money into military spending. Because you know, there is a huge difference between owning 100 nuclear warheads, 2,00 strike aircraft, 100 long range bombers, 2 aircraft carriers, etc and what is more closer to reality: thousands of nuclear warheads, thousands of war planes and more than 15 nuclear powered aircraft carriers. Funny how other countries are much safer, without a fraction of that kind of military.
then shifting taxes to the rich (businesses and capital) as we have been doing for decades
Are you living on the moon? The taxed haven't been shifted to the rich. They're the ones getting the largest tax breaks.
(the poor and middle class pay virtually no taxes)
Utter nonsense. Someone making 50k will pay a higher tax rate than millionaires who don't even work. Those who sit on their asses while their money makes more money for their little personal empire.
has led to the problem we are in now. Blame it on the Democrats and other Socialists? 100%
Only if you think FOX News and the mantra from talk radio has more credibility than the majority of economists. I tend to value education more than that.