Clinton enters Super Tuesday with reduced lead

Washington: Barack Obama reduced Hillary Rodham Clinton's once strong lead going into Tuesday's coast-to-coast presidential primary contests, while Republican frontrunner John McCain aimed to lock down his party's nomination by squeezing Mitt Romney out of the race.

McCain had a substantial lead in polls on the Republican side, but the Democratic race was far from clear.

A CNN/Opinion Research poll out on Monday had Clinton narrowly leading Obama 49 per cent to 46 per cent, within the poll's 4.5 per cent margin of error.

The same poll had McCain far ahead, 44 per cent against 29 per cent for former Massachusetts governor Mitt Romney, with former Arkansas governor Mike Huckabee trailing at 18 per cent.

Exhausted White House hopefuls launched one last frenzied day of campaigning before a 24-state Super Tuesday - the biggest one-day White House nominating contest in history.

Meanwhile, McCain was looking to beat Romney on his home turf. on Monday, he was taking his campaign to Massachusetts, a state where Romney served as governor, as he looked to knock out the former businessman on Super Tuesday when Republican contests are in 21 states.

The Arizona senator looks to do well among moderate northeastern Republicans after his victory in Florida's primary last Tuesday led former New York Mayor Rudy Giuliani to quit the race and endorse McCain. He also has backing from Arnold Schwarzenegger, governor of the key state of California.

Gone from McCain's recent campaign stops was a mention of Romney, who McCain recently has lumped in with the Democrats on the question of when US troops should leave Iraq.

"The first thing we've got to do after Tuesday [today] is unite this party," McCain says repeatedly these days - as if the 21 states holding caucuses and primaries this week are simply a formality.