Democratic presidential nominee Hillary Clinton leads Republican rival Donald Trump by 12 percentage points among likely voters, her strongest showing this month, according to a Reuters/Ipsos opinion poll released on Tuesday.

The Aug. 18-22 poll showed that 45 percent of voters supported Clinton, while 33 percent backed Trump ahead of the Nov. 8 election…

The poll also found that about 22 percent of likely voters would not pick either candidate. That lack of support is high compared with how people responded to the poll during the 2012 presidential election between Democratic President Barack Obama and Republican Mitt Romney.

“Those who are wavering right now are just as likely to be thinking about supporting a third-party candidate instead, and not between Clinton and Trump,” said Tom Smith, who directs the Center for the Study of Politics and Society at the University of Chicago.