Eternally endearing themselves to people who spend a lot of time looking at polls, CNN and its partner ORC surveyed before, between and after the two parties’ conventions last month.

Before both conventions, Hillary Clinton had a 7-point lead. She got support from 89 percent of Democrats, while Donald Trump got 93 percent of the vote from Republicans. Independents were the difference-maker, backing Clinton by 10 points.

Between the conventions, Trump took a 3-point lead (this was after the GOP convention, which came first). He got 90 percent of the vote from Republicans to Clinton’s 88 percent from Democrats, but independents flipped to back Trump by 13 points.

After both conventions, Clinton was back on top by 9 points. She had a 9-point advantage among independents, but her support from Democrats had gone up to 96 percent. Trump’s support had fallen to 89 percent. Why the difference between her pre- and post-convention leads? That softening Republican margin.