CA state tax exempt interest from U.S. obligations in a mutual fund

Vanguard says 64% of vmrxx interest income is from federal obligations. It breaks that down further into 29% U.S. Treasury and 34% Fed Home Loan.

Is 0%, 29%, or 64% of the interest income state tax free in California?

I’m obviously overthinking this, but I’m more academically interested in the answer at this point!

Case for 64%:

“If mutual fund (it is) is >50% U.S. or State municipal obligations, enter the amount of tax-exempt interest dividends that are attributed to U.S. obligations”

Vanguard also shared this document specifically stating that this fund meets the 50% requirements and gives instructions to use 64% exempt as a percentage.

Case for 28%:

CA does not consider Federal Home Loan Mortgage Program as U.S. obligations, leaving only the 28% paid to U.S. Treasury

Case for 0%:

Since CA doesn’t count Federal Home Loan as a U.S. obligations, then VMRXX mutual fund has <50% of its interest from U.S. obligations and the interest is therefore not statetax exempt.

Vanguard says 64% of vmrxx interest income is from federal obligations. It breaks that down further into 29% U.S. Treasury and 34% Fed Home Loan.

Is 0%, 29%, or 64% of the interest income state tax free in California?

I’m obviously overthinking this, but I’m more academically interested in the answer at this point!

Case for 64%:

“If mutual fund (it is) is >50% U.S. or State municipal obligations, enter the amount of tax-exempt interest dividends that are attributed to U.S. obligations”

Vanguard also shared this document specifically stating that this fund meets the 50% requirements and gives instructions to use 64% exempt as a percentage.

Case for 28%:

CA does not consider Federal Home Loan Mortgage Program as U.S. obligations, leaving only the 28% paid to U.S. Treasury

Case for 0%:

Since CA doesn’t count Federal Home Loan as a U.S. obligations, then VMRXX mutual fund has <50% of its interest from U.S. obligations and the interest is therefore not statetax exempt.