How can there be a fiscal squeeze if they always have access to more debt?

I suppose you could say that the treasury still has to find buyers at its auctions.

Interest as a percent of tax receipts doesn't look like too big a squeeze:

Edit: at first I only found a chart through 2022. Then I found this one through 2024, definitely looking worse:

but it does seem more like a squeeze here:

I'd be curious to see both these charts with 2025 on them.