May's job report is really great news for America, but really bad news for Democrats. Here's why.

President Donald Trump promised on the campaign trail to bring real life back to the American economy, and if May's jobs report is any indication of his work nearly 18 months into office, Trump has certainly succeeded.

The report showed the American economy is growing toward a very prosperous future. And according to CNBC, that's really great news for everyone — except Democrats.

Why is it bad for Dems?

As CNBC reported, as politicians nationwide ramp up their campaign efforts ahead of November's midterm election no issue "is more important than the perennial issue of employment."

"Voters who are employed are historically more likely to favor incumbents than those who are out of work," CNBC reported.

Indeed, May's report showed the economy added 223,000 jobs in May, pushing the unemployment rate to just 3.8 percent, a level not seen in 18 years.

In addition, the unemployment rate among African-Americans dipped to 5.9 percent, a drop of nearly one whole percentage point from April's 6.6 percent. As NPR noted, the gap between the overall unemployment rate and the rate among African-Americans has never been smaller.

More from CNBC:

Most troubling for Democrats is that the biggest job gainers have been groups that have historically suffered from stubbornly high levels of unemployment, including younger workers, black workers and so-called marginally attached workers, whose employment is tracked by the BLS with the so-called U-6 rate. That measure includes part-time workers who want a full-time job and people who want to work but have given up looking and aren't in the official count of the labor force.

That paints a very bleak future for Democrats, who are organizing to retake a majority in Congress, if not just the Senate where the Republican majority is much smaller than in the House. And to make matters worse, experts predict the historic job boom may go on for years.

"Business is coming alive. This could go on for a whole bunch more years, in my judgement," White House economic advisor Larry Kudlow told CNBC.