Fast Food worker Daniella Longchamps, right, of Baltimore demonstrates along with other activists during a protest outside the National Restaurant Association's 28th Public Affairs Conference at the Ronald Reagan Building and International Trade Center in Washington on Tuesday. (Alex Wong/Getty Images)

It has been a long time since the White House got the kind of good economic news that arrived on Friday morning with the latest jobs report. How real those numbers turn out to be and how much they boost Democrats’ chances of holding down their losses in November are now the questions of the moment.

Democratic strategists have been arguing for some time that the key to the November elections is to make the economy the focus of their political message. Through polling and focus groups, they’ve come away believing that the contrast between the two parties is best drawn on economic issues and on policies that affect the middle class.

That’s why President Obama and Vice President Biden have used their White House megaphone to try to paint Republicans as doing the bidding of the most affluent in society — and why the president has used his executive authority to try to produce more economic activity. That’s why Senate Democrats pushed for a vote to raise the minimum wage last week, only to be rebuffed by the Republican minority, which blocked consideration of the legislation.

The latest Washington Post-ABC News poll underscored why Democrats see these economic contrasts as a central plank in their November strategy. By 52 to 32 percent, Americans trust Democrats over Republicans on helping the middle class. By 49 to 33 percent, they say Democrats are closer to their position on whether the minimum wage should be raised.

Casting Republicans as insensitive to the broad middle class is a page straight out of the Obama 2012 playbook. It worked for the president, in part because he had an ideal foil in former Massachusetts governor Mitt Romney — a wealthy businessman who too often played into the stereotype of an out-of-touch rich guy. Whether that strategy translates into the state-by-state contests that will determine who controls the Senate after November is quite a different question.

Friday’s jobs report from the Bureau of Labor Statistics suggested that the economy roared into a different gear last month, adding 288,888 jobs. That’s the best single month of job growth since January 2012. At the same time, the unemployment rate plunged, from 6.7 percent to 6.3 percent.

The unemployment rate is now 1.2 percentage points lower than it was a year ago and the lowest since September 2008, the month that the collapse of Lehman Brothers triggered the worst financial crisis since the Great Depression. It’s no wonder administration officials were cheering, albeit cautiously, in their public statements.

The Democrats’ economic strategy — like the latest jobs numbers — comes with several important caveats. The employment report was released days after another report showed that the economy grew at an annual rate of just 0.1 percent during the first quarter. Much of that may be blamed on the brutally cold winter that gripped so much of the country so long, but do the April jobs figures represent a burst of pent-up activity or a an economy truly shifting into higher gear?

Quarterly changes in gross domestic product have produced uncertain signals about the health of the economy at many times over the past five-plus years. Federal Reserve officials apparently believed that the first-quarter numbers were misleading, announcing this week that they would cut their monthly bond purchases by another $10 billion — a vote of confidence that the economic recovery is gaining strength.

But there is also a troublesome aspect to the latest employment report. One reason the jobless rate declined by as much as it did is because another 800,000 workers simply dropped out of the labor market last month. The labor force participation rate fell by four-tenths of a percentage point, continuing a pattern during the long, slow recovery since the 2008 downturn. For comparison purposes, the participation rate in September 2008 was 66 percent. Today, it is 62.8 percent, which is 1.2 percentage points below where it was a year ago.

There’s no way to portray that as good news, and Republican congressional leaders were quick to seize on that finding in their statements about the jobs report.

Will last month’s burst in employment change public perceptions? That may be the key to the Democrats’ hopes of getting a political boost from the economy this fall. The Post-ABC poll and a new NBC News-Wall Street Journal poll showed that, whatever movements in the stock market or overall economic growth, public pessimism is still widespread.

In the Post-ABC poll, 71 percent of Americans rated the economy negatively. That can be read two ways. Taken by itself, it’s another indicator of an electorate in a sour mood — and a sour electorate often takes its frustrations out on the party that holds the White House.

Seen from a longer perspective, the 71 percent negative number doesn’t look quite so bad. Two months before the 2012 election, 81 percent of Americans rated the economy negatively. Weeks before the 2010 election, it was 90 percent. So, Democrats can try to console themselves by saying, “We’re making some progress.”

On the question of whether the country is moving in the right direction, a different pattern emerges. In the latest Post-ABC poll, 69 percent of registered voters say the country is seriously off track. In fall 2012, the percentage was decidedly lower, at 56 percent and had brightened considerably after August of that year. Romney is convinced that boost in confidence about the direction of the country was one big reason why he lost to Obama.

Through much of 2010, the year of the Democratic shellacking, the mood was deteriorating. On the eve of the midterm elections that year, 71 percent of registered voters said the country was off track, up from 62 percent at the beginning of that year. What’s important now is to see whether the electorate begins to feel better about the state of the country.

There is much talk right now about how the key to November is voter turnout and the Democrats’ disadvantage in midterm elections. That’s certainly important. But the state of the economy is fundamentally more important in any election year.

Friday’s jobs report doesn’t change the fact that Democrats are and will remain on the defensive between now and November. Whether the president and his allies can leverage the economic issue to their advantage will determine the degree to which they minimize their problems.