An upheaval in the US electoral scene has been caused by the candidacy of Kamala Harris, who now leads former president Donald Trump in three critical statesaccording to a New York Times and Siena College poll.

Kamala Harris leads Trump by four percentage points in Wisconsin, Pennsylvania and Michigan, with 50% to Trump’s 46%. The polls were conducted between August 5 and 9.

The polls, some of the first of high quality in those states since Joe Biden announced he would no longer seek re-election, come after nearly a year of similar surveys showing either a tie or a slight lead for Trump over Biden.

It appears that the Democrats are now in a much stronger position in these three states that are key to victory.

However, the results also show Kamala Harris’ vulnerabilities. Voters favor Donald Trump when asked who they trust to handle the economy and immigration, issues that remain central to the presidential race.