Kamala Harris and Donald Trump will meet for the first time in person at the debate
Kamala Harris gets a double poll boost just six weeks from the presidential election. AFP

Two major national polls are revealing a new boost for Democratic presidential candidate Kamala Harris, with her leading Donald Trump four points in one survey, and five points in another.

Harris has a five-point lead over Trump in a head-to-head race among registered voters (49 percent to 44 percent) in the latest national poll by NBC News.

That's a marked shift between the parties' candidates from NBC's poll in July when Trump was ahead by two points before President Joe Biden stepped out of the race.

The survey also shows a 16-point boost in Harris's favorability rating since July. That's the "largest increase for any politician in NBC News polling" since President George W. Bush's standing surged after the 9/11 attacks, the network noted.

Democratic support reached its highest point in NBC News polling since the middle of last year, while the share of voters saying they were undecided or wanted another choice dropped to its lowest point since then.

Seventy-one percent of all voters said in the latest poll that their minds are made up, while 11 percent noted they still might change their vote. In April 26 percent said they might change their vote.

Harris is seen as better than Trump as being competent and effective, as well as having the mental and physical health to be president, according to the poll. Harris also emerges in the survey as the candidate who better represents change.

"In July, there was a stiff breeze heading directly at President Biden and obscuring a clear path to victory. Today, the winds have turned in Kamala Harris' favor," said Jeff Horwitt of Hart Research Associates, the Democratic pollster who conducted the survey with Republican pollster Bill McInturff of Public Opinion Strategies.

Trump, however, still holds key advantages on the economy and inflation, although those leads are smaller than they were when Biden was still in the contest. The largest segment of voters in the survey — 28 percent — named inflation and the cost of living as their primary concern.

Threats to democracy, and immigrants and the border, were the second and third most important issues, though concerns about threats to democracy have climbed three percentage points since April, and fears regarding immigration were down about a third.

And experts warn that the race is still unpredictable. Republicans falling away from Trump, for example, could return to him even very late in the campaign.

The current race looks much like it did last time around, the NBC pollsters noted. The Democratic nominee is more popular than the Republican candidate, but electorate is nevertheless still deeply polarized, and the end unclear, they pointed out.

A new CBS News/YouGov poll finds Harris with a four-point lead nationally (52 percent to 48 percent) among likely voters, and a two-point lead (51 percent to 49 percent) among likely voters in battleground states (up from dead-even in the swing states a month ago).

Harris is gaining slightly as the number of voters feeling positive about the economy inches upward as interest rates and gas prices come down, the poll found. Harris does better with voters who have a positive view of the economy and of their own personal financial situation, according to the survey.

Support is evenly split (50-50) between the two candidate by voters who prioritize policies over personal qualities. Harris, however, far outpaces Trump (66 percent to 33 percent) among those who prioritize personal qualities, the poll found.

Politico dinged Trump and his campaign over the middling results for recently losing focus and for "flailing" messages and sometimes confounding positions, including confusing stances on abortion and covering child care costs.

That's even before the landmine of falsely accusing immigrants of eating people's pets in Springfield, Ohio, and Trump's angry attacks on hyper-popular Taylor Swift, who endorsed Harris.

"Whatever control and self-restraint helped launch Trump's third presidential campaign has largely disappeared in the crucial final stretch," the Washington Post's crack crew of political journalists recently reported, Politico noted.

The NBC News poll of 1,000 registered voters (860 of whom were contacted via cell phone) was conducted September 13-17. It has an overall margin of error of plus or minus 3.1 percentage points.

The CBS News/YouGov survey of 3,129 voters was conducted September 18-20. The margin of error is plus or minus 2.2 points.