Believe it or not, this might be the best news on polling that Donald Trump and his campaign will get this week. Suffolk’s new survey of Florida voters shows Trump in largely the same position he’s had in the state, but also shows Hillary Clinton with a nominal post-convention boost. She has hit her highest level of support in a month of Sunshine State polls, with a six-point 48/42 lead. But even with that, it’s only four points up from where she was at before the conventions in the NBC/WSJ/Marist poll, and two points up from Quinnipiac in mid-June from before James Comey’s statement. It’s a bounce just past a typical margin of error.

In looking at the polling from Pennsylvania, Allahpundit noted the large downward deviation on non-white voters in the polling sample — which didn’t help Trump at all. This poll’s sample looks more solid. The partisan split is 39/37/23 for a D+2, while 2012’s turnout model was 35/33/33 (a rounding issue makes it look like 101%); the ethnic split is 67/13/16 white/black/Hispanic, and 2012’s turnout was 67/13/17.

Given that, and Suffolk’s track record, this looks like a credible poll result. And the news isn’t all bad for Trump; if polling aggregation in Florida is any indication, this would suggest that he hasn’t lost any traction, but simply hasn’t gained any, unlike in New Hampshire and Pennsylvania. After the Democratic convention and the Trump campaign’s own-goals over the past week, that might be an encouraging result.

In a four-way race, Trump and Clinton fare slightly worse at 43/39. However, Gary Johnson only gets 4% of the vote, and Jill Stein comes in less than 3%. Undecideds go up from 9.4% to 11% in the four-way scenario, but it looks like the vast majority of Florida’s votes see this election as a binary choice. Despite both candidates being under water in favorables, their supporters are extremely committed to them; only 3.8% of Hillary voters might consider Trump, and only 2.4% of Trump’s voters might give Hillary a chance. This state will be won or lost on the undecideds rather than exodus from one candidate to the other.

The demos tell a tougher tale for Trump. Hillary edges him among men, 46/45, and beats him handily with women 50/38. Hillary also narrowly edges Trump among independents 42/40. Trump only carries a plurality of the white vote at 48/41, and loses the minority vote by a large 26/64 gap.

One other result should worry Republicans. Almost 83% of GOP respondents in this poll voted in the closed primary, compared to 77% of Democrats. In contrast, almost 70% of independents didn’t bother to vote in either one, but of those who did, only slightly more voted in the Republican contest (13.2%) than the Democratic primary (10.5%).

The big primary turnout in Florida would therefore appear to be — as some surmised — not Trump creating thousands of new Republican voters, but simply turning out more general-election voters in the primary than normal. That would explain why his big primary turnouts haven’t translated to large general-election leads, and also indicates that Trump’s appeal might be passionate to a narrow slice of voters but not broad enough at the moment to win in swing states.

At any rate, Trump seems to have established a solid floor in Florida, and may have an easier time picking the pace back up if the campaign can broaden its appeal.