WASHINGTON -- Bleeding support from his own party, Donald Trump attempted to salve the gusher Monday with the balm of traditional Republican economic medicine: wide-ranging deregulation and tax cuts.

The Republican nominee proposed a plan to shrink government and grow the economy with an across-the-board regulatory reduction and tax cuts that would apply to wealthy estates, companies and several classes of individuals.

He would end American participation in the global climate treaty, scrap the current president's climate-change regulations and, according to a campaign document he released Monday, invite TransCanada Corp. to re-apply for a permit for the Keystone XL pipeline.

The announcements came in a detailed policy speech amid a series of brutal polls showing him struggling with upper-class and Republican voters, a problem illustrated by a first senator declaring Monday that she won't support her party's nominee.

Speaking in Detroit, Trump appealed to nostalgic Republicans by comparing his policies to those of party hero Ronald Reagan. One thing Trump didn't address was how he'd avoid a less-heralded legacy of the Reagan years -- the near-tripling of the U.S. federal debt, as spending cuts never kept pace with his tax cuts.

Of his proposed moratorium on new federal regulations, and his request for every federal department to eliminate old growth-hampering ones: "It is time to remove the anchor dragging us down. And that's what it's doing -- dragging us down."

The speech also included elements aimed at the more left-leaning shades of the political spectrum. He reiterated his promise to renegotiate NAFTA, said his daughter Ivanka was working on a plan to make child care tax-deductible, and proposed ending a carried-interest loophole tilted toward the wealthy.

But the big-money promises were borrowed heavily from the traditional Republican recipe-book.

He proposed ending the estate tax, which applies to a tiny percentage of families that bequeath more than $5 million. That measure would immediately reduce U.S. federal revenues by 0.6 per cent, but lead to greater economic growth, according to analysts from the non-partisan Tax Foundation.

He would model his income-tax plan on the one proposed by conservatives in the U.S. House of Representatives, reducing the rate for top-income earners by six per cent, with three per cent reductions for middle-income earners. The similar House Republican plan would reduce federal revenues by trillions, but according to the Tax Foundation spur longer-term growth of 9.1 per cent of GDP.

Trump would go even further in cutting corporate taxes than House Republicans. He would bring the U.S. rate, one of the highest in the world, from 39 per cent down to 15 per cent -- far lower than Canada's, and lower than the House GOP's proposed rate of 20 per cent.

It remains to be seen whether his invoking Reagan's legacy will bring the Gipper's disciples back to the fold. Several alarming bits of news Monday illustrated Trump's problems with the upper crust of his own party:

  • A new Monmouth University poll was the latest to show him losing badly -- this one by 13 percentage points nationally. Republicans were a big reason for that. He only had support from 79 per cent of self-described Republicans, compared to Hillary Clinton who had 92 per cent of Democrats onside. Trump was losing college grads by 24 per cent, women by 28 per cent, and was even losing among respondents making over $100,000.
  • A Republican senator announced she won't be voting for Trump. Following the lead of some colleagues in the House of Representatives, Susan Collins of Maine described him as cruel and incompetent. She referred to him mocking a disabled reporter, insulting a judge of Mexican heritage and getting into a spat with the family of the late soldier Humayun Khan. "The unpleasant reality that I have had to accept is that there will be no 'new' Donald Trump," she wrote in an op-ed column in The Washington Post. "Regrettably, his essential character appears to be fixed, and he seems incapable of change or growth."
  • Trump was repudiated by 50 people who worked in national security under Republican administrations. Several famous Republicans signed an open letter saying they would not vote for Trump because he's erratic, ill-informed, unqualified, and would endanger the country as president.
  • The chief spokesman for the Florida Republican party announced he was quitting to take a position with an outside conservative group because he wants to avoid working for Trump.

One consistent plank of his economic platform is clearly at odds with the U.S. Chamber of Commerce wing of the Republican party. Trump continued his attack on trade deals. He promised not to join the Trans-Pacific Partnership, and said of NAFTA: "If we don't get a better deal, we will walk away."

He didn't mention another Canadian file in his speech -- the Keystone XL oil pipeline. A highlights package of his economic plans, released by the Trump campaign, said he would invite TransCanada (TSX:TRP) to renew its permit application.

The Calgary-based pipeline company is suing the U.S. government for cancelling the project, saying President Barack Obama's refusal to grant a permit was arbitrary and driven by politics.

The company says its agreements with landowners along the route remain in effect, and that the project could be restarted.