Rigged elections? Nasty woman? Trump's scorched earth tactics have little upside

He passed on the opportunity.

Instead, he chose on Wednesday to stay with the strategy he has employed during recent weeks: Pump up his hard-core supporters and hope that's enough to win.

He suggested he might not accept the election result if his Democratic opponent Hillary Clinton wins on Nov. 8, called her a "nasty woman," and repeated hard-line conservative positions on issues such as abortion and immigration.

While that kind of rhetoric was catnip to his passionate, anti-establishment base, it is unlikely to have appealed to independent voters and women who have yet to choose a candidate.

"When you're trailing in the polls, you don't need a headline the next morning saying that you're not going to accept the election results," said Ford O'Connell, a Republican strategist who supports Trump.

With less than three weeks left in the race, Trump is behind Clinton in most battleground states and is under-performing in almost every demographic voter group compared to the Republican nominee, Mitt Romney, four years ago. Party strategists had said before the debate that he needed to use the event to draw in voters beyond his hard-core supporters.

Trump didn't listen or perhaps didn't care.

His debate was a continuation of his apparent strategy to ensure his most fervent supporters show up on Election Day, while betting that his attacks on Clinton's character and truthfulness will discourage voting by already sceptical young and liberal Democrats.

But experts who study voter behaviour warned that his attacks on Clinton may backfire, saying he may instead awaken Democratic voters who have so far been uninspired by Clinton.

"The risk he faces by engaging in a scorched-earth policy is that he activates people rather than turning them off," said Michael McDonald, who runs the U.S. Election Project at the University of Florida.

McDonald, who tracks early voting returns and absentee ballot requests, said he is seeing larger than expected surges of support for Clinton in southeastern states such as Virginia, North Carolina, and Florida.

The Reuters/Ipsos States of the Nation project, which uses a massive online opinion poll to project election outcomes in all 50 states, estimates that Clinton has a 95 percent chance of winning the election by about 118 votes in the Electoral College if it were held today.

It is against this backdrop that Trump has apparently decided to double down on energizing his base rather than broadening it. But the poll results cast doubt on the wisdom of that strategy.

If Trump's core white, male, working class supporters vote at high rates, as expected, that likely won't be enough to win. Trump, for example, already does well with white men who are at retirement age. Nine out of 10 of them are already expected to vote, according to the polling results, so, there is little room to squeeze out more votes.

Voting rights activists have accused Trump of trying to suppress voter turnout by claiming, without evidence, that the election has been rigged against him. He has also said his supporters need to monitor polling stations to ensure a fair vote, which the activists decry as an act of intimidation.

Should Trump's comments succeed in discouraging some Democratic voters from turning out, that may also not be enough to help him secure the White House. He still loses under what could be considered a dream scenario for the Republican nominee: white men show up in greater numbers than expected, while turnout among racial minorities is lower than expected.

In this scenario, the States of the Nation project estimates that Trump would win the battleground states of Ohio and North Carolina, and he would have a shot at winning Pennsylvania, Wisconsin and Colorado. Even then, Clinton would still have an 82 percent chance of winning the election.

There's yet another risk to Trump's strategy. By claiming the election is rigged, he could be unintentionally signaling to his supporters that voting no longer matters.

Michael Sopko, 63, a mortgage broker from Denver and a Trump backer, said before the debate that he sees his vote as pointless.