Every year, assuming you're a citizen and you accrue some sort of monetary income, you're required by the Internal Revenue Service to complete a form called a "1040" and formally declare your earnings. Then you need to figure out exactly how much you owe the government in taxes, hunt for any legal deductions to your declared taxable income, and through your own math figure out whether you owe additional money to the government, or if you had paid too much the prior year and request a refund. Aside from the fact that we're doing the taxman's job in essentially billing ourselves, what's even stranger is that it all works on the "honor system". The government will believe you and just take your word for it 99% of the time, aside from the "random" audit where one particular individual is scrutinized and made an example of to the rest of the community. If your math is wrong, and the government finds out, you go to prison for "tax fraud" or "tax evasion".
Imagine if other organizations and businesses operated this way. Suppose you're at a supermarket and after wandering about for an hour or so, you arrive at the register with a cart full of food. The cashier looks at you and asks you "What do you owe me?". You pay what you've determined to be the value of the food and if you're lucky, you make it out the front door un-harassed. But every now and then, security singles someone out and takes a scanner to each and every product in their cart and if it doesn't match their payment receipt exactly, the police are called and you're hauled off to prison. Is that any way to run a business, nevermind a whole country?
Assuming everything goes well and your math is correct, or wrong and undiscovered, you have no control whatsoever over where your money actually goes. You're assumed to be paying for a tiny fraction of everything our local and federal governments do. That includes police and firemen, roads, parks, research grants, wars, and a global surveillance apparatus... not to mention clandestine operations, the funding of militant groups to fight the militant groups our rivals are funding, and a decades-long "War on Drugs".
And this is where the corruption begins. Because the citizens have no way of knowing exactly where their tax dollars are being spent if they don't want to pour through books and books worth of legalese to find every piece of "pork" in every bill that's brought to the floor, our elected officials can spend that money wherever they like. They can't put it in their own pockets directly of course, so they take bribes in the way of future jobs/board appointments and kickbacks from corporate lobbyists, appropriating funds for their related corporate interests. Rarely does a bill become law without a host of edits to fund various local projects like libraries, stadiums, bridges, fiber cables, research into the mating habits of moose, etc. Most of this is public and if you have no life whatsoever, or it's your job, you can do a lot of research and find out how much money is wasted every year trying to make the right people happy so a particular politician can get re-election funding and do the whole dance again.
Imagine if we could control where our tax dollars went. Every year when we're doing the taxman's job, we could also do a secondary government service and fill out another form detailing exactly what we want our particular tax payments to be spent on, be it the military, schools, health-care, NASA, roads, or even payments on the principle of our national debt instead of just the interest, with a base 10% automatically going into a discretionary account the government could use on unforeseen expenditures. We could detail exactly how much money from our own personal tax payments we wanted to go into these individual government spending accounts and the government would be unable to use the money from one account on anything other that what it was intended for. In this way the true will of the people would be expressed each year.
The real magic however, is that the corruption would end. A lobbyist could ask for money, but there would be no money to give. The war-monger might want to jump into every conflict that arises across the globe, but there might not be enough citizens who want to pay for it. We would have a properly funded education system and roads for the first time in remembrance, and things like this..... would never get funding. And yes, that's a "T" before the "illion".