Powerful German state leaders from Friedrich Merz’s party have rallied behind him as speculation builds that his days in office may be numbered.The chancellor’s hold on power has looked increasingly shaky since a bombshell regional election result earlier this month in which the far-right Alternative für Deutschland (AfD) party routed his Christian Democratic Union (CDU) party in Saxony-Anhalt.With two more states heading to the polls on Sunday where the AfD is expected to perform well, Merz cancelled a plan to speak at the UN general assembly in New York next week because “his presence is required in Berlin”, a government...