WASHINGTON — The Democratic Party and 18 senators are objecting to a broadcasting company's plan to air on 62 TV stations a critical documentary about John Kerry's (search) anti-war activities after he returned home from Vietnam three decades ago. Sinclair Broadcast Group (search) has asked its television stations — many of them in competitive states in the presidential election — to pre-empt regular programming to run the documentary as part of an hourlong program two weeks before the Nov. 2 election. Based near Baltimore, the company owns or manages affiliates of major broadcast networks in several states, including Ohio, Florida...