Hillary Clinton may be surging in national polls, but in the key swing states of Florida, Ohio and Pennsylvania, Donald J. Trump remains in striking distance. According to a group of surveys of likely voters released on Tuesday by Quinnipiac University, Mrs. Clinton holds a one percentage point lead in Florida, a four-point lead in Ohio and a 10-point lead in Pennsylvania over Mr. Trump. The polls, which had a margin of error of plus-or-minus three percentage points, are slightly closer when Gary Johnson and Jill Stein, the Libertarian and Green Party nominees, are included. (please see link for full...