What to think of the latest PPP poll in Wisconsin?  On one hand, a narrow lead within the margin of error on the day before an election might signal a slight and final shift in momentum in Tom Barrett’s favor.  On the other, PPP is a Democratic pollster who might be looking for the best possible take on the race — and having the Democrat down three as a best case would be a positive for supporters of Scott Walker.  The Hill reports on the results:

A new poll finds Republican Wisconsin Gov. Scott Walker with a narrowed lead over Democratic challenger Tom Barrett ahead of Tuesday’s recall vote.

A Public Policy Polling survey released Monday shows Walker with the support of 50 percent of likely voters, ahead of Milwaukee Mayor Barrett at 47 percent.

But Walker’s support is down from a 50 to 45 percent edge in the same poll conducted three weeks ago and down from the seven-point 52-45 lead Walker held in a Marquette Law poll released last week.

PPP compares itself to Marquette as a way to argue for a changing electorate too, but that’s a false comparison.  One can make comparisons within a survey series for that kind of argument, as PPP also does when noting the change from the 50/45 from three weeks ago in its own polls, but a comparison against another pollster as a series is invalid.  It’s worth pointing out, too, that even within the PPP series, a change from 50/45 to 50/47 is statistical noise, well within the margin of error. It’s basically no change at all.

PPP’s own internals don’t support an analysis that Walker has lost momentum, either:

Walker has a 51/47 approval rating. He’s up with men (55-42), whites (52-46), seniors (58-39), and especially voters in the Milwaukee suburbs (70/29).

Barrett has a 46/46 favorability rating, improved from 43/46 on our first poll after the primary. He’s winning with women (52/46), minorities (58-36), young voters (53-39), those in Milwaukee County (61-35), and ones in greater Madison (59-37).

This is a close race, closer than it was a couple weeks ago. Scott Walker’s still the favorite but Barrett’s prospects for an upset look better than they have in a long time.

That is an exercise in spin.  First, as noted, the topline results haven’t changed at all in the statistical sense.  Second, Barrett only leads women by six points and barely holds a majority among younger voters — and that’s good news for a Democrat?  Walker has majority approval statewide, holds a +13 among men, and wins by almost 20 points among seniors.  Barrett’s only getting 59% in “greater Madison,” which one presumes would be the area of Dane County most densely populated with public employee union members.  Meanwhile, Walker’s taking 70% of the suburbs around Barrett’s own city.

Turnout will definitely be key, but don’t take too much from this last PPP poll.  The change in status PPP claims is overblown, and the internals point entirely to a different conclusion than a heightened chance of an upset.

Update: For some reason, I confused “greater Madison” with Madison County.  Madison is in Dane County. I’ve fixed the reference above.