The trend of the President's campaign speeches probably will be indicated in addresses he will deliver Tuesday at the West Point graduation exercises, and on Wednesday at a Flag Day celebration, following a prepared-for parade here. Administration leaders said tonight that they expect the campaign to be carried on a long dignified line, with the President paying little attention to personalities, and dwelling on the legislative achievements of the last three years, the fact that the United States is at peace, and the prosperity of the nation. The President finished his work on the platform today, and approved a draft of Senator James's speech as permanent chairman. Senator James and Senator Walsh, who leave for St. Louis tomorrow, will convey the Democratic leaders there the President's impressions of today's conventions. The President has not yet begun consideration of a successor to Justice Hughes on the Supreme Bench. He is said at the White House tonight that the President could make up his mind quickly, but as the Supreme Court recesses on Monday until October it was thought likely he would not hurry in making it clear. Justice Hughes's successor will be the choice of the President.  Third member of the court named by President Wilson. The resignation to say leaves five Republicans and three Democrats on the court. It is expected that Mr. Wilson will appoint a lieutenant. 