What is the difference of “Has it right” from other affirmative expressions such as “It is right,” “It holds, “and “It makes sense”?
Solution 1:
I understand X has it right to often be a stronger statement than given in Hellion's answer. I do agree with him that exactly right is definitely a much stronger statement.
Saying: "The Supreme Court has it right on violent video games.* tells me that at least on that one issue, they have the correct perspective and understanding of the whole collection of issues surrounding violent video games. That deep understanding is demonstrated in their decisions, but once I realize that they have it right, I am more likely to trust other decisions they announce in that area.
The difference between X has it right regarding Y and the other affirmative statements you listed are that has it right is a statement about X while the other affirmative statements are about Y.
Saying: "The Supreme Court's decision on violent video games is right." doesn't tell me much about the Supreme Court. They might have arrived at a good decision after starting with a flawed understanding of the issues.
Solution 2:
To have it right means that, in general terms, you are doing the correct thing or providing a proper path or giving the right answer. You may not have the perfect plan/answer, unless you have it exactly right, but you have demonstrated understanding of the situation and sound reasoning to arrive at a plan or conclusion that is correct on all the major concerns.
If your plan or answer makes sense, it's not necessarily the right answer or the best plan, but reasoning suggests that research or experience would probably show that it does turn out to be correct. Having your plan hold water or hold together is basically the same thing; it's not necessarily being confirmed as correct, but it appears consistent with the facts and likely to work out to the desired result.
If your plan or answer is right, that means that, according to the one claiming that it's right, it is the correct choice, or the one that they believe is the best.