In culminating moment, Biden is vice president

WASHINGTON — Joe Biden, whose foreign policy expertise, Washington savvy and personal style earned him Barack Obama's trust and faith, was sworn in Tuesday as the 47th vice president of the United States.

With the world watching, Biden raised his right hand and took his oath of office from John Paul Stevens, associate justice of the Supreme Court. The longtime Delaware senator is now a heartbeat from the presidency, a counselor to Obama, and one of the government's key ambassadors to other global powers.

In traditional form, Biden swore to defend the Constitution against all enemies with true allegiance to the cause, to take on the obligation freely, and to faithfully discharge the duties of the office.

"So help me God," Biden said, to an outpouring of cheers from the Capitol platform and crowds below.

Biden shared a few thankful moments with his wife, Jill, and other members of his immediate family. He shared a handshake with Obama shortly before the president-elect took his own oath of office.

The vice president's most vital role is to assume the presidency in the event Obama cannot serve. Beyond that, his duties can be limited or expansive based on the wishes of his boss, the president.

Biden says he plans to loyally support Obama but also wants an active role in decision-making.

The 66-year-old Biden served 36 years as a Delaware senator.

He and his wife began Inauguration Day by attending a private service at St. John's Episcopal Church with Obama and the incoming first lady, Michelle Obama. The four then headed to the White House for coffee with President George W. Bush and first lady Laura Bush, Vice President Dick Cheney and his wife, Lynne, and leaders from Congress.

Elections are not built around or decided by running mates, and given the enormity and the history of the moment surrounding Obama on Tuesday, Biden will retain second billing.

But his ascendancy to the vice presidency is a major turning point for the country too as Biden replaces Cheney, who assumed huge powers under Bush.

Cheney was a major voice on war and harsh interrogation techniques of suspected terrorists, and insists the Bush administration kept the nation safe; Biden accused him of doing more harm than any elected official in recent memory in "shredding the Constitution."

All that will be quickly be history, but Biden expects to play his own active role.