CHARLESTON, W.Va. – Wearing a flag lapel pin, Barack Obama emphasized his patriotism and support for a strong and humane military Monday, while Hillary Rodham Clinton implored West Virginians to sustain her hopes and implied that the Democrats could lose in November if her rival wins the nomination.

Mr. Obama expects Mrs. Clinton to win today's primary in West Virginia, which has large numbers of working-class voters. He used his visit to Charleston to combat critics' claims that he is not patriotic or ready to be commander in chief, in part because he never served in the military, usually doesn't wear a flag pin and opposed the Iraq war from the start.

He criticized Republican presidential candidate John McCain for opposing a Democratic bill to expand education benefits for veterans.

"At a time when we're facing the largest homecoming since the Second World War," Mr. Obama said of veterans returning from Iraq and Afghanistan, "the true test of our patriotism is whether we will serve our returning heroes as well as they've served us."

Meanwhile, Mr. Obama picked up four more superdelegates Monday, and his recent wave of endorsements puts him within reach of the nomination by the end of the primary season on June 3 – even if he loses half of the remaining six contests.

Mr. Obama's campaign announced Monday that he will visit politically neglected Michigan this week and Florida next week as he pivots to a general election strategy. It will be his first time in either state since signing a pledge nine months ago not to campaign in the two states that violated party rules with early primaries.