The chairman of the McCain campaign in New York, Edward Cox, waded carefully into the politics of national security yesterday morning as he warned that the city could face another calamity if voters make the wrong choice this November. Mr. Cox, a lawyer who considered a run for Senate in 2006, made the case that the coming election would turn on national security, contrary to the conventional wisdom that the economy is likely to dominate the campaign between senators McCain and Obama. “This is a serious world situation,” Mr. Cox told a New York delegation breakfast here in Minneapolis, before rattling off a list of global crises for which he said Mr. McCain would be much better prepared to handle. “If we don’t select the right person as the next president, we’re going to have more tragedies like the one we suffered in New York on 9/11,” he said. Mr. Cox also suggested that a campaign focused on national security could make New York competitive. “Now that we’re having the first national security election since 1988, New York will again be in play,” he said. The McCain campaign has sworn off politics at the Republican National Convention in light of Hurricane Gustav, which made landfall on the Gulf Coast yesterday. Mr. Cox began his remarks by noting the hurricane and praising Mr. McCain’s decision to curtail the convention. While he made little mention of Mr. Obama, his speech offered a clear argument for Mr. McCain.

BIDEN RETURNS TO CAMPAIGN IN HOMETOWN OF SCRANTON

Senator Biden, campaigning in his boyhood town of Scranton with his 91-year-old mother yesterday, gave voters a short course on the political climate as he grew up, saying that “to be Irish was to be Catholic was to be Democrat.” “This is where my family values and my faith melded,” Mr. Biden, the Democratic nominee for vice president, told about 75 hand-picked supporters. “The one thing you learned here is, a promise made is a promise kept.” Earlier in the day, Mr. Biden nixed plans to march in a Labor Day parade in Pittsburgh, saying he needed to focus instead on Hurricane Gustav’s landfall on the Gulf Coast. Asked about the Bush administration’s storm preparations, Mr. Biden said, “So far I’ve been impressed.” Mr. Biden lived in Scranton until 1953, when his father moved the 10-year-old and other family members to Delaware to search for a better job. His mother, Jean, and a brother, Jimmy, joined him at the three-story home as Democrats sought to shore up support in Pennsylvania, a perennial battleground. Four years ago, the Democratic nominee, John Kerry, made Scranton his first campaign stop after accepting the nomination. And Mr. Biden peppered his acceptance speech last month with references to his roots in Scranton, which boasts many socially conservative Democrats who largely spurned Mr. Biden’s running mate, Senator Obama, in the primary in favor of Senator Clinton.

DELEGATES ATTACKED BY PROTESTERS IN ST. PAUL

Protesters attacked delegates, smashed windows, punctured car tires, and threw bottles yesterday, a violent counterpoint to an otherwise peaceful anti-war march at the Republican National Convention. Police wielding pepper spray arrested at least 56 people. The trouble happened not far from the Xcel Energy Center convention site, and many of those involved in the more violent protest were clad in black and identified themselves to reporters as anarchists. They wrought havoc by damaging property and setting at least one fire. Most of the trouble was in pockets of a neighborhood near downtown, several blocks from where the convention was taking place. Police estimates of the crowd shifted several times during the event, ranging from 2,000 to 10,000. The crowd was clearly in the thousands. Late yesterday afternoon, long after the antiwar marchers had dispersed, police requested and got 150 Minnesota National Guard soldiers to help control splinter groups near downtown. Members of the Connecticut delegation said they were attacked by protesters when they got off their bus near the Xcel Center, KMSP-TV reported. Delegate Rob Simmons told the station that a group of protesters came toward his delegation and tried to rip the credentials off their necks and sprayed them with a toxic substance that burned their eyes and stained their clothes. One 80-year-old member of the delegation had to be treated for injuries, and several other delegates had to rinse their eyes and clothing, the station reported. Five people were arrested for lighting a trash bin on fire and pushing it into a police car, a St. Paul police spokesman, Tom Walsh, said. Authorities didn’t have immediate details on the other arrests.