Welles was able to pull off his hoax in 1938, but nobody could do the same today.
why do you agree and disagree ?

I agree because before people are so innocent and any information from an authority will make them believe directly. However, the generation today, people are so hard to please and are not swayed directly by bits of information. People need something in order to believe and they want really a clear and a visual evidence in order to listen and be attentive. Also, people now are more aware and educated as compared to before. 

This is a complete adjective clause. 

Ineed my points srry