A poll is the process of voting in an election. To win your vote in the election, politicians make rosy promises about the changes they will make if they are voted in. The words they use as they make these promises is a 'pitch' - words used when trying to persuade someone to believe, buy or accept something,
as in 'a good sales pitch'.
The politicians used words that they hoped would persuade you to believe them and the promises they were making - in the campaigns, it was all 'pitches and promises' from the candidates, and none of them talked about the national issues that really concerned the voters.