US polls: Trump, Clinton in lead heading into key Iowa caucuses

Washington: Heading into the crucial Iowa caucuses that will officially kick off the race for the White House tomorrow, controversial Republican presidential aspirant Donald Trump and Democrat Hillary Clinton have leads over their respective opponents after days of political bickering.

The Iowa caucuses loom tomorrow the first votes after 1,500 candidate rallies, 60,000 TV ads and a nail-biting tightening of the polls here.

The state's voters are poised to play a significant role ever in both parties' nominating contests.

The final polls before the Iowa caucus, released by the prestigious Des Moines Register newspaper in association with Bloomberg show a different story for the two front-runners - Trump, 69, and Clinton, 68. While Trump has overtaken Senator Ted Cruz from Texas in this latest Iowa poll, Clinton has a slim edge over Senator Bernie Sanders.

"Donald Trump has muscled ahead in Iowa, regaining his lead on the brink of the first votes being cast in the 2016 presidential race," the Des Moines Register said. Trump has support of 28 per cent, while Cruz follows him with 23 per cent. In a previous poll released on January 13, Trump (22 per cent) had trailed Cruz (25 per cent).

"Trump is leading with both the inner core of the caucus universe and the fringe -- that's what any candidate would want," said veteran Iowa pollster J Ann Selzer, who conducted the survey.

On the other hand, the poll showed that Clinton's lead over Sanders is very slim. The former secretary of state is the favourite of 45 per cent of prospective Democratic caucus-goers, while 42 per cent support Sanders. As a result, many see this as a dead heat in the Democratic Party.

"This race is as tight as can be. If Bernie Sanders had momentum headed into the final month, the race now is static and essentially tied," said national political strategist David Axelrod.

The poll conducted by Selzer has long been influential and accurate. Selzer's surveys predicted victories by Barack Obama and Mike Huckabee in 2008, and foresaw Rick Santorum's late surge in 2012, it said.

Meanwhile, the influential New York Times daily has endorsed Clinton and the lesser-known John Kasich as the respective Democratic and Republican presidential candidates.