John McCain, the all-but presumptive Republican nominee, told conservative activists this afternoon that he cannot win the presidency without "dedicated conservatives." "I know I have a responsibility to unite the party," he said. He acknowledegd that he has had differences with many conservatives but said he hopes they will see that he has the record of a true conservative. "I am proud to be a conservative," McCain said. ... McCain spoke to the Conservative Political Action Conference in Washington just hours after Mitt Romney used the same venue to announce he is suspending his presidential bid...