The opening round of the presidential nominating season begins tonight in schools, churches, fire stations and living rooms across the state of Iowa.

After millions of dollars of television ads, endless phone calls from campaign phone banks and non-stop campaigning by the candidates, the Des Moines Register summed up that atmosphere here this morning with a headline that read: "It's up to you Iowa, Let the voting begin."

Tonight's precinct caucuses mark the first step in a process that will officially end next summer at the Republican convention in Philadelphia and the Democratic convention in Los Angeles, when the two parties formally anoint their nominees for president.

Kayne Robinson, the Iowa Republican party chairman, said this morning that Iowa voters give the candidates "a different look" than some of the bigger states to follow. "We scald them like a chicken and take their feathers off," Robinson said. "It's pretty hard to be a phony after 20 or 30 visits."

Vice President Gore and Texas Gov. George W. Bush remain the favorites to win tonight's caucuses, which will be held at roughly 4,000 locations throughout the Hawkeye state.

The final Des Moines Register Poll showed Gore leading Bill Bradley 56 percent to 28 percent, with the remainder undeclared. Among Republicans, Bush led with 43 percent, followed by Steve Forbes with 20 percent. Alan Keyes, John McCain, Gary Bauer and Orrin Hatch were in single digits, although the fiery Keyes has been drawing big crowds in the final days of campaigning here.

Bradley, who has been complaining that he was up against Gore's "entrenched power", told ABC television this morning that Iowa "is a difficult state because it's bigger than New Hampshire, there are more media markets in New Hampshire, it is a state [with] a lot of distance between place to place."

Gore and Bush hope to use their anticipated caucus victories to give them a boost heading into New Hampshire, whose Feb. 1 primary marks a crucial test for both Bradley and McCain. Each would like to become the first candidate in a contested nomination fight to win both Iowa and New Hampshire since Jimmy Carter in 1976.

Bush said late Sunday a victory for him in Iowa would signal the "beginning of the end of the Clinton era."

"In 24 hours the people of this state begin to cast a vote which will be the beginning of the end of the Clinton era in Washington, D.C," Bush declared.

Iowa has been an uneven predictor of nominees in past years. Ronald Reagan lost here in 1980 but still won the nomination. George Bush, the father of the Texas governor, ran third here in 1988 but still won the nomination. Democrat Dick Gephardt won Iowa that same year, but lost the nomination to Michael S. Dukakis.

With the caucuses not scheduled to begin until this evening (8 p.m. EST for the Republicans and 8:30 p.m. EST for the Democrats), the candidates were up early this morning for a series of final appearances.

Arizona Sen. McCain joked with reporters, campaigning in New Hampshire, about his decision to bypass the Iowa caucuses, and expressed no regrets. "People of New Hampshire don't pay a great deal of attention to what happens in Iowa," he said at the start of a day of five events, including a rally to celebrate New Hampshire's first-primary status.