New polling from one of President Trump’s most favorable pollsters, the Trafalgar Group, shows a dead heat in key swing states in the race for the White House.

The survey found that Trump leads Ms. Harris 47 percent to 45 percent in Pennsylvania, 47 percent to 46 percent in Wisconsin, and 47 percent to 47 percent in Michigan.

The results in each state are within the margin of error, with the polling results, but coming from one of a handful of pollsters that tend to overestimate Republicans’ support. The findings confirm that the race rests on a knife’s edge going into the final stretch of campaign season.

Another Republican-leaning pollster, InsiderAdvantage, also found that the race was virtually tied in the swing states across the south.

The pollster found that in Arizona, Trump leads Ms. Harris 49 percent to 48 percent, and Trump leads 48 percent to 47 percent in Nevada.

In North Carolina, the pollster found that Trump leads 49 percent to 48 percent, and that the race is tied, 48 percent to 48 percent in Georgia. Again, all of the InsiderAdvantage findings are within the margin of error. 

While all of the polling suggests that the race is close in all of the swing states going into the last two months before the presidential election, there has been a decisive shift in favor of Ms. Harris since her entry into the race.

In the RealClearPolitics polling average, Ms. Harris has enjoyed a steady increase in support since entering the race and she currently leads Trump 48 percent to 46 percent, nationally.

Other polling aggregators also show Ms. Harris ahead in national polls, with FiveThirtyEight’s polling average showing Ms. Harris ahead 47 percent to 44 percent over Trump.