In a nutshell, fairly so.
The ISCTE-ICS poll for SIC and Expresso newspaper, which is the only, that undertakes face-face interviews came closer to the result, predicting correctly the 1% margin between AD and the PS and giving CHEGA 17%, which is only 1% off from the results today.
The poll also came close to the results of the smaller parties, only mixing up their position in terms of votes, placing the Liberals in 5th place, when they came on 4th place; the Left Bloc 4th when in reality they came 5th; and underestimating Livre's vote share.
However, all the other polls that were conducted closer to election day predicted that the margin between the AD and the PS would be greater, largely at the expense of CHEGA. For this reason, many analysts expected the AD to win by a comfortable margin and CHEGA to have a worse result than initially predicted. They were wrong, obviously.
Party | Católica/Público/RTP/Antena1 (March 8) | Intercampus/CMTV (March 7) | Aximage/JN/DN/TSF (March 7) | ISCTE/ICS/ SIC/ EXPRESSO (March 1) | Interim Results (March 10) |
AD | 34% | 29,3% | 33,1% | 31% | 29,49% |
PS | 28% | 23,3% | 29,6% | 30% | 28,66% |
CHEGA | 16% | 15,6% | 16,7% | 17% | 18,06% |
IL | 6% | 7,8% | 3,9% | 4% | 5,08% |
BE | 5% | 5,5% | 6,6% | 5% | 4,46% |
LIVRE | 3% | 4,3% | 1% | 2% | 3,26% |
CDU | 5% | 3,7% | 4% | 3% | 3,3% |
PAN | 1% | 2,1% | 2% | 2% | 1,93% |