Well, I got to thinking about this in the context of how much money I spent in taxes and charitable contributions last year.
Now most of this ended up not mattering in the end because the standard deduction was larger than all of my potential itemized deductions, but one of the things did actually cost me some extra taxes.
In 2018, I paid $1,216 in local property taxes, $905 in sales taxes, and effectively 7.2% of my income in federal income tax.
According to my records, my charitable contributions (only counting the ones that can be deducted, which is essentially US-based 501(c)(3) organizations) came to $8,255. (Not all of this is SF fandom related, by the way.) That of course doesn't include the time I've spent as a volunteer with various SF fandom-related functions, since you can't deduct the value of your time.
I even kept close track of any gambling wins and losses, and thanks to adroit use of free-play coupons and a decent conversion rate into real money*, I had around $350 in gambling income, and our family also earned around $50 in what is usually called "hobby income" from the freelance writing and photography we did for Locus. Most people probably don't report those small amounts, and I admit that if I didn't keep good track of my finances in Quicken, I probably wouldn't do so, either. But I'm not sorry that it cost me about $29 in extra income tax to do this.
My point is that would I follow the law (beyond what I think most people would do) and contribute so much if I didn't care about my own country?
It isn't necessary to be a right-wing, MAGA-hat-wearing, white neo-confederate Manly Manly Man Who is Manly with a gun fetish to be a patriotic American, although that particular subset seems to be trying to hijack the label for themselves. Like the current occupant of the White House, they've mistaken "nationalism" for "patriotism," and we'll all poorer for it.
*If you get a $10 free play coupon (from which you can't cash out the free portion, only actual winnings beyond it) and have $0 at the end, you've earned nothing, nor have you lost anything. But if in the same case you have $17 (which is usually my goal because I'm trying to pay for my breakfast), then that's ordinary gambling income. Personally, I'm surprised I've done that well, considering how much I spend on keno and how we didn't hit any nice wins in 2018 the way we did the previous year.