US election: Kamala Harris boosted by surprise poll lead in Iowa

A shock poll from the state of Iowa has added another swing state to the list of US election battlegrounds as Kamala Harris and Donald Trump fight for every last vote.

The Des Moines Register poll, which landed on Saturday evening, puts Harris 3 points ahead in the state, which has not voted for a Democrat for president since backing Barack Obama in 2012.

It carries a mere six votes in the Electoral College, but losing it would greatly complicate Trump's path to the presidency as he seeks to peel as many states away from Harris and the Democrats as possible.

While the poll is an outlier, it carries outsized significance because of its source: Ann Selzer, whose Iowa-based polling firm is highly esteemed for its accuracy in polling the largely rural state in previous years.

According to the survey, the last that Selzer will oversee in Iowa before the election, Harris appears to be pulling ahead of Trump largely because of her exceptionally strong lead among college-educated white women, many of whom are furious about the dramatic rollback of abortion rights since the advent of Trump's first presidency.

Iowa has banned abortions after the sixth week of pregnancy, a point where many women do not even know they are pregnant.

While it allows exceptions in cases of rape, incest, serious foetal abnormality or a threat to the mother's life, the ban is highly unpopular even with many usually disengaged women voters and swing voters who have previously backed Republicans.

When the Selzer poll was released, it immediately drew the attention of the US political media. The Trump campaign quickly fired off a press release contrasting it with another poll that showed their candidate with a healthy lead in the state.

The nationwide polling picture shows a race effectively tied, with neither Harris nor Trump establishing an unassailable lead in the seven main swing states: Wisconsin, Michigan, Pennsylvania, North Carolina, Nevada, Georgia and Arizona.

However, record-breaking early voting figures in numerous states have left some observers questioning whether the polling industry is able to accurately model the makeup of this year's electorate.

In addition, several typically safe states have seen relatively little presidential polling even since Harris took over the Democratic campaign from Joe Biden in the summer.