President Donald Trump's approval rating in March jumped to 42% from 35% in last month's poll, and congressional Republicans have closed the gap on the generic ballot from a 16-point deficit in February to just 6 points in March.

On its face, it appears like Trump and Republicans suddenly got more popular since February, despite all the Trump scandals and bad press.

Recall, however, that CNN's January poll found that Trump's approval rating was 40% and congressional Republicans were down 5 points. Those numbers are much more in line with CNN's March poll, with the difference between 40% and 42% in Trump's approval rating and a 6- and 5-point deficit on the generic ballot for congressional Republicans not being statistically significant.

So to paraphrase legendary NFL coach Vince Lombardi , just what the heck is going on here? Are Trump and congressional Republicans really on the rise or is it only a statistical illusion?

The answer is a little from Column A and a little from Column B. The President and congressional Republicans are up, but not by as much as it may seem when first glancing at the latest CNN poll.

The way we know this is by aggregating all the polls that come out in a given month. These polls are of differing quality but aggregating a lot of polls helps to shrink the sampling margin of error and control for the occasional outlier result you should get when you interview about 1,000 Americans.

In aggregating, we see that the Trump's approval rating in March has averaged 41% and congressional Republicans are, on average, down 8 points on the generic ballot. Both of these are very close to what CNN's poll found.

February's average had Trump's approval rating also at 41%, while the average generic ballot poll had Republicans down 7 points. January's average placed Trump at 40% approval and Republicans down 8 points on the generic ballot.

In other words, the President's approval rating across all the polls over the last three months has been around 41%. The average Republican disadvantage on the generic ballot has been right around 8 points. These are right about where the average CNN poll has been over the last three months.

So are Trump and the GOP completely steady? Not quite. While Trump's approval rating over the last three months has been around 41%, it has increased from the second half of 2017. In every month but September (when he averaged an approval rating of 39%), Trump's approval rating was 38%.

The generic ballot has been more jumpy (in part because we have fewer polls to average), but we see the GOP is up here as well. Congressional Republicans were down 11 percentage points in December and 9 points in November.

The difference between 38% and 41% for Trump and 8 and 11 points on the generic ballot over many polls is statistically significant. These are not necessarily huge jumps, however.

And it is important to remember that Trump is still the most unpopular president at this point in his term.

We can say pretty definitively, though, that the President and congressional Republicans are in a little better shape today than they were at the end of 2017.

The question then becomes why Trump and congressional Republicans are up, even with a seemingly unfavorable news cycle.

The answer, like many things in politics, is probably a combination of a number of factors.

As I've noted before, much of the negative news coverage recently that has focused on aspects of Trump only reinforce what people already think about him. For example, there's the matter of Trump's alleged affair with Stormy Daniels. Most voters already didn't believe that Trump was faithful to his wife, so Daniels detailing her alleged affair with Trump on national television won't necessarily give people new information to make them change their mind of him overall.

There's also the matter of the economy. Trump has consistently been viewed better on the economy than he has on most other issues. Now, though, Trump is getting more credit for the state of the economy than he had been. In Quinnipiac's two latest polls on the subject , more Americans think that Trump is responsible for the economy than former President Barack Obama. Last year, more people thought Obama deserved more credit.