Projection Update: Mainstreet 9/6-8

The following poll has been added to the model:
Mainstreet's 9/6-8 national poll (current weight among national polls: 36%)
Update Sept. 10: Partial regional figures from this article and this article included.
New update Sept. 10: Full regional breakdown (and exact decided+leaning sample sizes) now included.
For a full list of included polls, see previous Projection posts.

Only the national numbers and partial regional figures are publicly available, so this update moves parties up (mainly LIB, a bit GRN) or down (mainly NDP and BQ, a bit CON) more or less uniformly across Canada. The ON numbers are great for the Liberals, but adding them did not move the needle much more than just adding the national numbers, probably because Mainstreet's two previous polls also had very strong ON numbers for the Liberals. The good Prairies and BC numbers for the Tories and good Atlantic and QC numbers for the Liberals, on the other hand, were news to the model.

As a whole, the poll has a significant impact on the projection.

Projection as of the latest national poll (midpoint: September 7)
LIB - 166.3 166.7 166.5 (35.4%)

CON - 142.7 142.6 143.2 (36.3 36.4%)
NDP - 14.1 14.0 (11.2%)
BQ - 10.4 10.1 9.8 (4.2 4.1%)
GRN - 3.6 3.5 (9.7%)
PPC - 0.5
IND - 0.4
If you're new to my 2019 projections, view key interpretive information here.

It will be interesting to see if this shift, the largest in a month for a single projection, holds.

Seats changing hands since the last projection:
- In QC, LIBs take Jonquière and Trois-Rivières from CONs.
- In QC, LIBs take Pierre-Boucher--Les Patriotes--Verchères from the BQ.
- In ON, LIBs take St. Catharines, Northumberland--Peterborough South and Vaughan--Woodbridge from CONs.
- In ON, LIBs take Windsor West from the NDP.
- In AB, CONs take Edmonton Strathcona from the NDP.
- In BC, LIBs regain Burnaby North--Seymour from CONs.
- In BC, CONs take Cowichan--Malahat--Langford from GRNs.