If they had not been so hateful and politically motivated, what would have happened?

God knew what would happen, but because He gave us all free-will, had they accepted their king, the prophecies concerning the death of Messiah would have been fulfilled in another way. After the transfiguration when Moses and Elijah speak with Messiah about his exodus from this world (Luke 9:31), His ministry changes and be begins using the phrase "this wicked generation" and "the son of man will rise on the third day" It was as if fate was determined about that time and Messiah did not resist it, he actually told Judah to "go, do what you're about to do." He also said it would have been better that the man who betrayed him was never born.

May his days come to be few, may his dispensation be taken by another. May his sons become orphans and his wife a widow. May his sons rove, yea rove so that they must beg and may they be driven out from their deserted homes. Psalm 109:7-10

Woe to that man...

Papias (early church father) reports that Judah was not successful in hanging himself, but died as recorded in Acts in a most disgusting manner, parallel with Psalm 69:23-25. Essentially in his guilt, he ate so much food that it killed him "May his table become a trap before him and a repayment and a snare..." The psalm describes his waist becoming "bowed low" and "his home became desolate".

Judas did not die by hanging, but lived on, having been cut down before choking. And this the Acts of the Apostles makes clear, that falling headlong his middle burst and his bowels poured forth. And Papias the disciple of John records this most clearly, saying thus in the fourth of the Exegeses of the Words of the Lord:

From Papius, disciple of John:

Judas walked about as an example of godlessness in this world, having been bloated so much in the flesh that he could not go through where a chariot goes easily, indeed not even his swollen head by itself. For the lids of his eyes, they say, were so puffed up that he could not see the light, and his own eyes could not be seen, not even by a physician with optics, such depth had they from the outer apparent surface. And his genitalia appeared more disgusting and greater than all formlessness, and he bore through them from his whole body flowing pus and worms, and to his shame these things alone were forced [out]. And after many tortures and torments, they say, when he had come to his end in his own place, from the place became deserted and uninhabited until now from the stench, but not even to this day can anyone go by that place unless they pinch their nostrils with their hands, so great did the outflow from his body spread out upon the earth.

Woe to that man who betrays the Son of Man! Notice He didn't say "woe to all Jews" but "woe to that man".