How do I write a sentence that contains because and 3 independent sentences/reasons?
For example,
I wanted Leicester to win the league because they were underdogs; the other teams had spent more money; and I like the city of Leicester.
If I used commas instead of semicolons, would I not be guilty of comma splicing?
I would say no, semicolons are not appropriate here. Semicolons are used to separate what would be independent sentences, and the reasons here are logically separate, but not grammatically. For example, it wouldn't make sense to say
I wanted Leicester to win the league because they were underdogs. The other teams had spent more money. I like the city of Leicester.
All of those are grammatically correct sentences on their own, but they don't mean the same thing when separated - that is, they're syntactically correct this way, but not semantically correct. It's actually not a comma splice because they function as list elements, not really independent clauses.
So why isn't this a comma splice, if they look like independent clauses? A comma splice is the use of a comma to separate two independent clauses when there should be a conjunction. For example,
Tessa was crossing the square, she heard the church bells ringing.
But you do have a conjunction in your sentence - the word because - and that serves to connect the first clause and the list.
But, you might say, don't we use semicolons to separate list elements? Yes, but only when the list elements themselves contain commas. For example, this is unclear:
Present were Mr. Jones, the head of the choir, Theodora, and myself.
Are there four people here (Mr. Jones / the head of the choir / Theodora / me) or three? And if there are three, which one is the head of the choir, Mr. Jones or Theodora? Using semicolons to separate the list elements would make that clear.
But your list elements don't contain any commas themselves, so it isn't necessary to use a semicolon to disambiguate them.
