Tunisians voted on Monday on a new constitution promoted by President Kais Saied, which has been criticised for giving his office nearly unchecked powers and threatening to install an autocracy in the birthplace of the Arab Spring. The referendum comes a year to the day after Saied sacked the government and froze parliament in a power grab that his rivals condemned as a coup. His moves were however welcomed by many Tunisians fed up with a grinding economic crisis, political turmoil and a system they felt had brought little improvement to their lives in the decade since the 2011 overthrow of di…