Not true. You are expected to tithe even now, but that's not the point. The point is, why would you give and brag about it on your 1040? Your right hand should not know what your left hand is doing. I know many people in my church that don't record their giving. I'm one of them. It's nobody's business what I give to God. Why would anybody even care what I give? I don't need the tax deduction, so why post it? Keeping your giving secret is a Biblical principle as old as the Widow's mite.
What we have here is Trumpsters embarrassed that Trump rarely even goes to church and doesn't study his Bible. Trump hasn't even made his taxes available. I'm sure when they come out, there will be millions given to one charity or another. Does God care if you gave a million to the NYC Center for the arts? Or how about, The Clinton Foundation? That's not the church. All of it will just appear on a line on his 1040 and that's what the news will report.
Another thing,...I could be a total confessing atheist and give 50% of my income to the Temple of Baal and it would be a tax deduction on my 1040. Does that somehow make me a "good person"? I'm sure it will come out that the Clinton's give hefty sums to their charity, The Clinton Foundation, to bolster their retirement. Does that make them good people?
I can assure you Cruz is more "Christian" than Trump has ever been. I live in Texas, he's my Senator, and I have followed his career since his Solicitor General days. He's a good man and he's not a liar.
What I never liked about giving is that in the Eastern Orthodox church I grew up in, you make a “pledge” and they give you envelopes with your “number” on it which they use to identify you with. I think it should be a personal matter.