To quote the Manhattan forum:
'because of' answers WHY questions:
sample 1-'Because of his intolerant attitude, that politician always seems to be attacking the poor.'
Why does the politician seem to be attacking the poor?
>> because of his intolerant attitude
sample 2-'The number of acres destroyed by wildfires, which have become an ongoing threat due to drought and booming population density, has increased ....'
Why have the wildfires become an ongoing threat?
>> because of drought and booming population density
'due to' answers WHAT questions:
sample 1-'The team's win today was due to better conditioning'
What was the cause of the team's win today?
OR
What was the team's win today due to?
>> better conditioning (noun)
Another way of looking at it:Due To:This phrase modifies adjectives/adjectival phrases/nouns.
for example : His failure is due to his laziness.
Because of : This phrase modifies the verb.
for example : He failed because of his laziness.
Hope this helps