Not that a Court can't find its way to reach just about any concusion, BUT

This argument has been around as long as the lottery industry has been around.

By definition, a tax is something you must pay, or you face some sort of government sanction or force. An earlier comment said that if you don't want to pay a tax, avoid that action or behavior. That's a little too simplistic...there is a difference between things like income and property taxes where the right to seek wealth and property are guaranteed ("the pursuit of happiness") and the right to engage in allowed commerce (e.g. buying cigarettes and gasoline) that is regulated.

If you don't pay income taxes, they will come after you. If you don't pay property taxes, they take your property.

If you don't play the lottery - no sanction at all. Therefore, the Lottery is not a tax.

The (questionable) right to pursue happiness doesn't mean you're also free of any obligation that  might result. Earning enough that you have to pay taxes is completely voluntary, and it is that simple. If you want to avoid income tax you have the legal right to do so by not earning enough. Only if you choose to earn enough, will you have to pay income tax. Property tax, and taxes on alcohol, cigarettes and gasoline are other things that result in an obligation to pay a tax, but only if you choose to buy the product.

Buying lottery tickets works the same way. You aren't required to buy any, but if you choose to buy them the government will charge you for them, and the charge is mandatory.

So, if you don't pay for your lottery ticket they may come after you.

If you don't earn an income (or buy cigarettes alcohol, or gas) - no sanction at all.

 I'm not suggesting that there's a strong argument that the lottery is a tax. I'm simply pointing out that all taxes are imposed as result of doing something that is voluntary, such as earning an income, owning property, or buying some product. The fact that buying lottery tickets is voluntary isn't what will decide whether or not the cost of a ticket qualifies as a tax.

OTOH, the proceeds that go to the state when somebody voluntarily buys cigarettes, alcohol, or gas is a tax. Common sense may say that lottery tickets are a product, but in considering that the purpose of lottery tickets is to raise money for state coffers, a court could find that the proceeds are effectively a tax, just as the state's proceeds from other products that are bought voluntarily. 

The voluntary nature of a lottery ticket purchase may not determine it's status, but saying something is effectively a tax doesn't make it a tax either.  There are many ways to raise reveune and fill state coffers which are not taxes.  The state of North Carolina can tax a lottery ticket.  They can meet in Raleigh and vote to tax lottery tickets like they tax other products.  They haven't done so.

Governments these days are much more into fees.  They don't like to be in the press for supporting an increase in taxes so they impose fees on things to pay the bills.  A fee is not a tax, and saying it is effectively a tax doesn't again make it a tax.  Only a tax is a tax, and the NC Leg. did not pass a lottery tax bill.    Only taxes which are called taxes are actually taxes.  Another example is they commonly use gas taxes to pay for highway construction.  What happens when it's not enough - let's put up toll booths!  Is a toll booth charge a fee, or a tax?    Neither really, it's a toll.  You don't pay - they come after you.  Just another way to raise money but you can't itemize tolls on your Federal Schedule A, like you can other true state taxes such as sales tax or income tax. 

 If I can itemize money spent on lottery tickets on my Schedule A I might be willing to call it a tax - but that ain't happening.  In that scenario I wouldn't declare winnings as gambling income either - it would be a 'tax refund'.