Blowing past a billion

Less than four months until Election Day, the battle for the White House already has crossed the $1 billion mark — as the presidential candidates, political parties and the two super PACs closely aligned with President Obama and Republican rival Mitt Romney race to collect political cash.

The biggest spending is yet to come in a presidential race that could hit an eye-popping $3 billion, said Bob Biersack of the Center for Responsive Politics, which tracks campaign money. Much of it may never be fully disclosed as it flows through "social welfare" groups active in politics this year.