ISTANBUL — Turkey’s self-styled strongman president suffered a serious setback after voters unexpectedly backed a string of opposition parties in Sunday’s parliamentary elections.Recep Tayyip Erdogan, who has dominated the political scene for more than a dozen years, campaigned on behalf of his former party, the Islamist-rooted Peace and Development Party (AKP), appealing to voters to elect at least 300 parliamentarians to help push through a constitution that would expand his powers as an executive.
