WASHINGTON – President Barack Obama remained on the offensive Tuesday on the pace and shape of legislation reinventing health care, against stiffening opposition from Republicans and growing wariness among rank-and-file congressional Democrats. Following a recent pattern, harsh public exchanges ricocheted along Pennsylvania Avenue from the White House to the Capitol amid laborious work on the measure that Obama has insisted be put together before Congress leaves in August for its recess — a timetable a House Democratic leader indicated was slipping. Entering a closed-door Democratic meeting, House Ways and Means Chairman Charles Rangel, D-N.Y., told another lawmaker: "No one wants...