A powerful opponent of the Declaration of Independence has emerged here on this fourth evening of July 1776 -- an opponent strong enough to rally the latent opposition to separation from the mother country. Mr. John Dickinson, Pennsylvania's leading delegate to the Continental Congress, has just told reporters that he intends to speak on the floor before the final vote is taken; this in a supreme effort to block this declaration which would commit our thirteen colonies to revolutionary war with England. Mr. Dickinson agreed that he is staking his political future on the outcome of the vote. He anticipates that if he fails to block passage of the Declaration of Independence, he will be ejected from the Congress and be removed.