TOKYO (Reuters) - Japan ruling party lawmaker Mieko Nakabayashi isn't just worried that her Democratic Party will lose power in next month's election; she fears a comeback by rival conservative Liberal Democrats will spell a return to the prolonged one-party rule that critics blame for many of the country's past policy ills. Three years after the Democratic Party of Japan (DPJ) ended more than half a century of nearly non-stop Liberal Democratic Party (LDP) rule, surveys suggest disappointed voters will hand the LDP the most seats in a December 16 poll for parliament's lower house. ...