(Denver) A tribute to ailing Sen. Edward M. Kennedy capped with a possible appearance by the liberal lion himself plus a sharp attack ad knotting Republican John McCain to President Bush were likely to raise the spirits of delegates on the opening day of the Democratic National Convention.

Kennedy, who is being treated for a malignant brain tumor, traveled to Denver late Sunday and was expected to attend the evening festivities, according to officials speaking on condition of anonymity because no announcement had been made. A video tribute had been planned because the senator hadn’t been expected to be able to travel to the convention.

Keeping up its offensive against McCain, Barack Obama’s campaign released an ad featuring images of McCain hugging Bush and the two smiling in spite of tidings of economic woe and McCain admitting he doesn’t know much about the economy. “We cant afford more of the same,” the spot warns.

McCain’s campaign also released an ad to play on what it sees as a weakness for Obama: his lack of support among some backers of primary opponent Hillary Rodham Clinton. Its new TV ad features a Clinton supporter who now backs McCain assuring like-minded voters: “A lot of Democrats will vote McCain. It’s OK, really!”

Opening night at the Pepsi Center, the main venue for the four-day convention, aimed to tell the Illinois senator’s personal story to the millions of voters nationwide who will begin tuning in to the presidential campaign. Obama’s wife, Michelle, was the evening’s keynote speaker.