No, even prophets are capable of missing it by a small percentage, because they misinterpreted a small portion. For example, his prediction that Republicans will take 9 Senate seats may include some they already possess. The number of Senate seats up for grabs are 35, of which 26 are held by Democrats. So you see what I mean? He is perhaps right that Republicans will grab 9 Senate seats, though he may have misinterpreted as gaining 9 Senate seats. Hopefully he gets 100%, but I will pay more attention to him even if he only gets 90% correct.
Not in God's economy. That's just an excuse to deceive the gullible.
Deuteronomy 18:15-22 “The Lord your God will raise up for you a prophet like me from among you, from your brothers—it is to him you shall listen— just as you desired of the Lord your God at Horeb on the day of the assembly, when you said, ‘Let me not hear again the voice of the Lord my God or see this great fire any more, lest I die.’ And the Lord said to me, ‘They are right in what they have spoken. I will raise up for them a prophet like you from among their brothers. And I will put my words in his mouth, and he shall speak to them all that I command him. And whoever will not listen to my words that he shall speak in my name, I myself will require it of him.
But the prophet who presumes to speak a word in my name that I have not commanded him to speak, or who speaks in the name of other gods, that same prophet shall die.’ And if you say in your heart, ‘How may we know the word that the Lord has not spoken?’— when a prophet speaks in the name of the Lord, if the word does not come to pass or come true, that is a word that the Lord has not spoken; the prophet has spoken it presumptuously. You need not be afraid of him.