Poker is just like every other game, skill altered by luck.
I don't think it's justifiable to call poker "a game of chance" or "a game of luck". Flipping a coin is a game of chance. A slot machine is a game of luck. Games where you are purely risking money with no skill involved are games of chance/luck. And this be proven.
Luck would be playing any two hole cards until the end of every hand without ever folding. In that specific playing style, you are relying on luck or chance to win. It would be mandatory you use this playing style because ANY decision making on your part would be a game of skill not luck. And even going all-in preflop is a decision. NOTE: For argument's sake I am ignoring the FACT that deciding to never fold is STILL making a decision.
Now, it is possible in a cash game that if you do this one time, triple your money and get out you can win. So a cash game has the potential to be a game of luck/chance IF you only play 1 or 2 hands like this.
However, it is literally impossible for you to win a tournament this way. At most you would make it through 1 or 2 orbits (remember, you can't go allin to scare people off the hand because then you are making a decision and not relying on luck).
So, no, poker is not a game of luck/chance it is a game of skill. Now, there is the fact that luck or chance has a play in whether or not a particular hand will win, and I'm not even going to use the cliche' "but over a thousands of hands . . ." My argument is this. ALL skill games are a game of skill effected by luck. A football (American) that is fumbled, falls directly back into the runner's hands, who then returns it for a touchdown is luck. In baseball, the BEST batting average of all time is Ty Cobb at 36.6% and last year the typical batting average was 24.8%. To me, that makes it a game of skill combined with luck. And finally, the stock market. All the skill in the world cannot guarantee a profit in the stock market, even when the stock market is on the rise, people still lose their shirts over bad decisions.
So if poker is a game of luck/chance then so is every sporting event and every business venture. If those are considered legal and if people are allowed to literally lose everything in pursuit of those activities then so should poker be considered a legal activity.