Indiana Jones is an original character from the movies. That said, he's certainly based on adventure fiction and movies from the 30's that inspired Spielberg.

Wikipedia says:

Spielberg told Lucas he was interested in making a James Bond film, but Lucas pitched him of an idea "better than James Bond", outlining the plot of Raiders of the Lost Ark.

Well, growing up in Germany with all my grandarents being more on the nazi side of WWII, I feel like the US idea of getting rid of nazis is that you just have to fight them like in WWII. It didn't work though. German society and politics was still very much made up of nazis afterwards. Sure, they got taken the power to act upon their ideology in the same way as before. What you need is a systemic change where fascist ideas don't have any space anymore, where emancipatory ideas can grow and where people are liberated in who they are and what they think. But the issue is, misogyny and racism like portrayed by the Indiana Jones movies are strictly opposed to emancipatory struggles. Giving discriminatory ideas like these too much space will again lead to more fascist tendencies. My point is, it isn't always black and white, nazi or not nazi. I have no idea if my grandparents were all nazis. They were just kids brainwashed into this ideology. My granddad fought in the Wehrmacht against the allies, but he was just 17. It is easy to say "punch nazis" or "kill nazis". But unless you have a clear cut enemy like in a political party or an opposing army, this gets messy pretty quickly.