Thousands of people have demonstrated against a convention of the far-right Alternative for Germany, blocking some roads and delaying the meeting’s start as the country's major parties launched their campaigns for next month's general election. A heavy police presence was in place in the eastern town of Riesa Saturday and officers cleared some protesters from the streets. The party formally nominated co-leader Alice Weidel as its candidate for chancellor by acclamation. Weidel, who was among those held up, thanked delegates for “defying the left-wing mob and getting here.” She has no realistic chance of becoming German leader as other parties refuse to work with her. Mainstream conservatives are leading the polls and are favorite to win the chancellery.