When Donald Trump said last week that he will double the American growth rate, his skeptics scoffed. The left doesn’t think 4 percent growth is possible because they never came close to that target under Obama.

But there’s no law of nature or economics that says America is doomed to anemic growth rates. We believe with the right policy fixes that fast growth is not just possible, but probable.

In the 1980s the Reagan agenda had quarterly growth rates of 6, 7 and even 8 percent. One month recorded 1 million new jobs. Now that’s a recovery. And Trump is right that if India and China can grow at 8 to 10 percent, surely we can aspire to half that growth rate.

Faster growth of the economy is imperative if America is to retain our world superpower status — especially given the new rivalry of fast-growing China. This requires the new Trump plan, which will take American competitiveness seriously.

Here’s how Trump will ramp up growth.

First, Trump will enact the biggest pro-growth tax cut since Ronald Reagan’s 1981 reform. Trump will simplify the tax code and significantly reduce marginal rates, encouraging investment and economic expansion. His proposed corporate tax rate of 15 percent would make it easier for American firms to repatriate earnings, bringing capital back to these shores.

The House tax bill is similar to Trump’s. We can get this through Congress in the first 150 days. The Tax Foundation says this will add about $150 billion in higher output.

Next, a pro-growth energy policy would develop all of America’s abundant resources — oil, natural gas and coal. Trump’s plan could make America the world’s No. 1 energy producer within five years, producing millions of new jobs and trillions of dollars of extra output — along with new royalty payments to the government. And we will not waste hundreds of billions of dollars subsidizing 500 million solar panels — mostly built in China.

ObamaCare is Obama-Gone. It’s the fastest-growing entitlement program of all, and it will be replaced with a consumer-choice health plan. This will cut costs for families and businesses by as much as 30 percent.

On the regulatory front, Trump wants to immediately repeal dozens of President Obama’s anti-business executive orders. At the top of the stack to go in the dust bin is the clean power plant law that has put tens of thousands of our coal miners out of work.

Trump would also bring an America-first, pro-business approach to economic policy. Having someone in the White House who knows how to run a business and meet a payroll has to be a psychological lift for this battered and bruised economy.

Stephen Moore is an economic advisor to Donald Trump and an economist with Freedom Works.