Try this. It works on the site you provided:
$(window).scrollTop($("*:contains('Are you a Lib Dem or Tory'):last").offset().top);
It finds last, deepest element that contains given phrase on the page and scrolls to it.
If you want to do the same thing without jQuery you need to use XPath becasue CSS didn't get contains()
selector.
window.scrollBy(0, document.evaluate("//*[text()[contains(., 'Lib Dem')]][last()]", document.body).iterateNext().getBoundingClientRect().top);
If you need to scroll to the first occurrece, not the last one, delete [last()]
from this code.
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