It is true that the unexpected often happens in the Ballon d'Or election but I have no doubt that Benzema will win this year and some former footballers have said the same.
Benzima had a total of 59 contributions in 46 games played with 44 goals and 15 assists in 46 games played. With goals in big games as well(Hat-trick against PSG coming back from a 1-0 loss to them). Sadio Mane, Vinicius Jr and Robert Lewandowski are other contenders but I don't think anyone has as impressive feat as Benzima. Who has been consistent throughout the year.
Usually the ones who wins Ballon d'Or is a player who has won beside the La Liga or the local Championship,also the Champions League and last time the Champions League was won by Real Madrid so most probably at a really high percentage rate the Ballon d'Or is going to Benzema.Lewandoski is a great player also scoring an insane number of goals but he lacks winning a major trophy this year beside Bundesliga so his candidature has something missing.It can happen anything at the voting but usually has happened that the player with most trophies won has also won this event.
It is important how productive this year has been for Ballon D'or. Lewandowski had a very good season. Likewise, he had a very good season with Benzema. But Benzema often saved Real Madrid at the last moment. Benzema is one of the players who have the biggest share in becoming champions of the Champions League. That's why I think Benzema will win over Lewandowski.