Because, as, since

[Bassim]

I am wondering if these sentences are correct?

1. Because the majority of the politicians lack a real contact with reality, they often make decisions which defy common sense.

Is it possible to use words "as" and "since" instead and write:
2.As the majority of the politicians lack a real contact with reality, they often...
or,
3. Since the majority of the politicians lack a real contact with reality.....

4. Because it was snowing heavily the guests had decided to postpone their departure.

Is it possible to use "as" or "since" instead and write:
5. Since it was snowing heavily the guests had decided...

Are these three words, because, as and since interchangeable?

[emsr2d2]

I am wondering if these sentences are correct?

1. Because the majority of the politicians lack a real contact with reality, they often make decisions which defy common sense.

Is it possible to use words "as" and "since" instead and write:
2.As the majority of the politicians lack a real contact with reality, they often...
or,
3. Since the majority of the politicians lack a real contact with reality.....

4. Because it was snowing heavily the guests had decided to postpone their departure.

Is it possible to use "as" or "since" instead and write:
5. Since it was snowing heavily the guests had decided...

Are these three words, because, as and since interchangeable?

I would say they are all acceptable.

[5jj]

There is often no real difference between the three words, and I agree with emsr2d2 that all your sentences are acceptable.

Clauses with 'as' and 'since' often begin the sentence, and often contain information that is known to the listener:

Since/As it was snowing heavily, the guests had decided to postpone their departure.

Clauses with 'because' often introduce new information, and often follow the main clause:

The guests had decided to postpone their departure, because it was snowing heavily.

Because-clauses, but not as- and if-clauses can stand alone in answer to a question:

Why had the guests had decided to postpone their departure?
Because it was snowing heavily.