You are implying that there are no moderate (or 'swing') voters, which is foolish when the big parties actively reach out for these people. Instead, issues get

You are implying that there are no moderate (or 'swing') voters, which is foolish when the big parties actively reach out for these people. Instead, issues get polarised. Both parties and candidates have several different issues, so voters' actual preferences depend on which issues are important to them. You also get tribal voters ("My family has always voted conservative") who are unlikely to care about the issues in any election, but these cancel each other out somewhat in a plurality or AV/IRV vote. Nevertheless, I hope we can agree that accurately modelling voting habits is complicated, not simple.