Hi, yes the example in your link and the code in "CMSWebParts\Polls\Poll.ascx.cs" is aimed for Portal engine!
YOU need to create your OWN CUSTOM MVC widget or control.
However you could still use it's code as an example on how to interact with the API!
the Portal Engine widget actually uses the following control: "CMSModules\Polls\Controls\View\PollView.ascx.cs"
I think you are looking for the following API calls:
getting POLL info:
PollInfoProvider.GetPollInfo(PollCodeName, PollSiteID, PollGroupID);
.Columns("AnswerID, AnswerText, AnswerCount, AnswerEnabled,
AnswerForm, AnswerAlternativeForm, AnswerHideForm")
setting a vote