MANCHESTER, England — The last 10 days have shown Keir Starmer and Kemi Badenoch to be in strangely similar straits. The leaders of Britain’s ruling Labour Party and opposition Conservatives went into their respective party conferences with rock-bottom expectations. Both stepped over that low bar, avoided any immediate threat to their jobs, and loudly delivered messages their members needed to hear — more muscular rhetoric against Nigel Farage’s populist Reform UK (Labour) and bolder policy on