President Trump has an ace in the hole that his opponents are forgetting. Again!

Despite all the sideshows — the alleged Russian interference in the election, obstruction of justice probes, ringers in Trump investigations and, of course, the president’s big mouth and poor judgment — Trump became president because of one thing: The US economy hadn’t been growing enough to please voters.

The sideshows (which I’ll get into later) continue, but the economy looks like it is doing better. So Trump is scoring points on the one issue that matters most to voters.

According to the official numbers, the economy is growing moderately well, compared with the weak growth during the Obama administration. The gross domestic product expanded at an annual rate of 3.3 percent in the third quarter in 2017. That followed the second quarter’s 3.1 percent.

So far, the fourth quarter is humming along at an annualized growth rate of 3.2 percent, according to projections.

Job growth has also been moderately good, although the hurricanes this fall are making it hard to determine just how good.

July produced a weak 138,000 new jobs, but August bounced back with 208,000 and October had 261,000. Only September’s hurricane-buffeted economy, which produced just 18,000 new jobs, appeared dismal.

Tomorrow, we’ll get the job figures for November. Wall Street expects growth of about 190,000 jobs. I don’t have a strong opinion, but November is one of the months that is not juiced by rosy assumptions.

The stock market, of course, has been booming. And it gained even more this past week as Republicans moved closer to tax cuts that may or may not help corporations — many of which already pay below the 20 percent tax rate targeted in the Senate version of the legislation.

Let me say this. I think the economic numbers are going to weaken and that the stock market is in an unsustainable bubble (enjoy it while it lasts). But the fact is that these numbers are in the background as Trump continues to face a barrage of shifting attacks.

So Trump may be at a crossroad.

If the economic numbers hold up, Trump-haters are going to have a hard time getting those who merely dislike him on their bandwagon.

If the economy weakens and the stock market goes down in a heap, the president is going to find a whole lot more people who won’t tolerate him.