Just six weeks ago, Hillary Clinton's advantage in the Electoral College looked insurmountable. Now, based on the latest round of public polls, it's a different story.

If the election were held today, Donald Trump would apparently win roughly as many electoral votes as Hillary Clinton — who held a commanding lead in early August and seemed to be closing off all possible Trump routes to 270 electoral votes.


But state polling averages, which can be lagging indicators, are beginning to show Trump in the lead. According to POLITICO’s Battleground States polling average, Trump is now ahead in Iowa and Ohio — and he’s tied with Clinton in vote-rich Florida.

A slightly more aggressive estimate could add Nevada, North Carolina and one electoral vote in Maine to Trump’s tally: The New York real-estate magnate is ahead in the most recent polls in Nevada and North Carolina, and in Maine’s Second Congressional District.

That, plus all the other states Mitt Romney won four years ago, would get Trump to 266 electoral votes — just four shy of the 270 needed to win. Clinton’s once-comfortable cushion has been deflated to such an extent that if Trump wins those states and the electoral vote in Maine, he only needs one more state to win — with Colorado, Michigan, New Hampshire, Pennsylvania and Virginia the most likely targets. And there’s recent polling evidence suggesting he is in striking distance in some of those states.

The analysis is based on the public polls — which, especially in the battleground states, have turned hard toward Trump this week, coming after a weekend of news stories about controversial Clinton comments and the furor surrounding her pneumonia diagnosis. Public polls, which usually don’t control for party identification or registration, tend to swing more violently during the course of the campaign than the campaigns’ internal data.

So far, there’s little evidence either campaign is adjusting their strategy based on their own fresh data. Trump is advertising on television in four states this week: Florida, North Carolina, Ohio and Pennsylvania.

Clinton’s campaign hasn’t reengaged in states where it pulled out earlier this summer. Despite closer polls, Clinton and the super PAC supporting her candidacy aren’t back on the air in Virginia, for example.

But the series of battleground-state polls that have shown Trump leading has led to a surge in GOP enthusiasm. In three live-telephone Ohio polls out this week, Trump was ahead by 5, 5 and 3 points. In Florida, Trump was ahead by 3 points in a CNN/ORC International poll. In Iowa, Trump led Clinton by an eye-popping 8-point margin in a Monmouth University poll released Thursday. Those surveys moved Iowa and Ohio into Trump’s column in POLITICO’s Battleground States polling average — and Florida is tied as of Thursday night.

If Trump were to carry those three states, it brings him to 244 electoral votes. Trump still trails in North Carolina by a 1.6-point margin in the average, but the most recent poll, from Suffolk University last week, showed him ahead. Adding North Carolina to his tally would give him 259 electoral votes.

Trump trails by 1.4 points in the Nevada average, but the most recent Monmouth poll this week showed him in the lead. If Trump won Nevada, that would be 265 electoral votes. And a SurveyUSA poll conducted for the Boston Globe and Colby College showed Trump 10 points up in Maine’s Second Congressional District — since Maine awards two of its electoral votes by congressional district, that would add another electoral vote to Trump's total even if he lost the state overall.

Putting Trump at 266 electoral votes leaves him one state away from clinching the presidency. And recent polls point to some cracks in the swing states that until recently looked like the Clinton firewall.

The most recent poll in New Hampshire (4 electoral votes), from NBC News/Wall Street Journal/Marist, shows Clinton ahead only by 1 point. A University of Mary Washington poll in Virginia (13 electoral votes) released on Thursday shows Clinton ahead only by 3 points. In Michigan (16 electoral votes), a poll conducted by in-state pollster EPIC-MRA for The Detroit Free Press and a handful of local TV stations shows Clinton with only a 4-point lead in a head-to-head matchup.

There hasn’t been much recent polling in the largest prize left on the table, Pennsylvania and its 20 electoral votes. The most-recent poll, from Quinnipiac University, showed Clinton ahead by 5 points.

National polls, meanwhile, still show Clinton ahead — including four major national polls out this week. And Trump still faces significant headwinds with specific demographic groups that could cap his rise further.

Just this week, Clinton leads by 1 percentage point in a Fox News poll released Thursday, 2 points in the CBS News/New York Times poll out earlier Thursday, 5 points in a Quinnipiac University poll released Wednesday and 5 points in the ABC News/Washington Post poll released on Sunday.

And while each of those polls represent a tightening race from the month prior, they also show Trump isn’t gaining ground with the voting blocs among which he has always been weakest: women, more educated voters and racial and ethnic minorities.

In the ABC News/Washington Post poll, Trump earns only 13 percent of the nonwhite vote, showing he isn’t making headway with a growing, traditionally Democratic constituency. But Trump is also lagging among more friendly GOP leaning groups: He wins just 46 percent of white women, including just 40 percent of white women with a college degree. (Mitt Romney won about 56 percent of white female voters in 2012, according to exit polls.)

The Quinnipiac poll was similar: Trump wins just 19 percent of the nonwhite vote, 46 percent of white women and 44 percent of white voters who graduated from college.

The race was closer in the two, more-recent polls out on Thursday, but Trump is struggling similarly among key groups. The CBS News/New York Times poll shows Trump winning only 40 percent of white college graduates and 45 percent of white women. In the Fox News poll, Trump only wins 15 percent of nonwhite voters and 40 percent of white college grads.

But Clinton has her challenges, too. In the Fox News poll, she only leads Trump by a 5-point margin among voters under age 35, 38 percent to 33 percent. (She actually leads Trump by 4 points among all voters 55 and older.)

While other polls show her further ahead of Trump among younger voters, perhaps most troubling is the number of younger voters who say they intend to support one of the two major third-party candidates. In the Fox News poll, it’s a combined 24 percent of voters younger than 35 who choose Libertarian Gary Johnson or Green Party nominee Jill Stein.

In the Quinnipiac poll, in which the four-way ballot test is asked as a subsequent question after the head-to-head matchup, a combined 44 percent chose Johnson and Stein. That hurts Clinton most: On the head-to-head ballot, she leads Trump by 21 points among younger voters, 55 percent to 34 percent. But her share of the young vote drops to 31 percent on the 4-way ballot, with Trump at 26 percent, Johnson at 29 percent and Stein at 15 percent.