Is there any number of illegal border crossings into the United States that would strike Democrats as an emergency?

As they resisted President Trump's efforts to stem the flow of illegal migrants across the U.S.-Mexico border, many Democrats made the point that fewer migrants are coming today than years ago, during the Bill Clinton and George W. Bush presidencies. The implication was that today's situation cannot be an emergency, because it used to be worse.

That doesn't make sense, of course. One could argue that crossings were an unaddressed emergency back then, and that today's figures, although lower, also qualify as an emergency.

But now, the border numbers are surging back to the bad old days. It appears that Customs and Border Protection apprehended more than 100,000 people in March (the precise figure has not yet been released), a pace that could mean more than 1,000,000 apprehensions this year.

For some perspective: According to Border Patrol statistics, U.S. authorities caught 1,643,679 people trying to cross the border illegally from Mexico in fiscal 2000. In 2001 the number was 1,235,718. In 2002 it was 929,809. In 2003 it was 905,065. In 2004 it topped the million mark again, with 1,139,282. In 2005 it was 1,171,396. In 2006 it was 1,071,972.

After that, due to a combination of slightly more assertive border security policies, plus, far more importantly, a massive economic downturn, the number of apprehensions began to fall. They hit a low point of 327,577 in 2011, leading many in Washington to assume that the problem — if they ever thought it was a problem — no longer existed.

[Related: Senate Homeland Security chairman blames DACA and court decisions for staggering border surge]

Then the number began to creep back up, to 479,371 in 2014. Then it fell back down in 2017, to 303,916. That was likely due to would-be migrants' fear that newly elected President Trump would get tough on illegal crossings. But the courts, resisting Democrats, ambivalent Republicans, and Trump's own lack of focus stopped any great progress on the border.

In a matter of months, migrants knew Trump could not stop them from entering the country illegally — and staying.

It should surprise no one that the numbers headed up again, to 396,579 in 2018. Now, crossings have gone through the roof, with 76,103 apprehensions in February of 2019 and 100,000-plus in March, numbers that could have come from the early- and mid-2000s.

And the numbers do not tell the whole story. In the Clinton-Bush years, the overwhelming number of illegal crossers were single, adult men trying to avoid detection as they sneaked across the border. When caught, they were quickly returned. So when 1.2 million were caught crossing, that did not mean that 1.2 million stayed in the United States.

Now, however, the nature of the flow has changed. Today, the large majority of those caught crossing are families and unaccompanied children. They are not trying to sneak in, they are crossing for the purpose of giving themselves over to the Border Patrol. They do that knowing U.S. law forbids them being returned, or separated, or even held for more than a few days. In short order, they are released into the United States.

It seems safe to say that more illegal crossers are staying in the U.S. than in the days of Clinton and Bush.

Yet Democrats steadfastly refuse to recognize that the situation constitutes an emergency. Instead, they accuse Trump of making the whole thing up. They call it a "fake emergency" and a "manufactured crisis" and every possible variant of those terms. And they reject the idea that adding barriers on the border will decrease the number of illegal crossings.

Formally announcing his presidential candidacy Saturday, Democrat Beto O'Rourke vowed to "find security by focusing on our ports of entry." Ports of entry are where the majority of illegal drugs crossing the border are seized, so that is indeed important. (And why Trump proposed new funding and technology for drug detection efforts at the ports.) But the 100,000-plus migrants crossing the border are not waiting at ports of entry. They are walking across the border in areas with inadequate barriers or no barriers at all. O'Rourke would not strengthen that security — he has actually said he would tear down some of those barriers.

The only Democrats who will admit there is a crisis are the ones no longer in office. Recently Jeh Johnson, who was President Barack Obama's last secretary of homeland security, said that while in office, he checked the apprehension figures every day. Noting that there was a recent day in which there were 4,000 apprehensions, Johnson said, "I know that a thousand overwhelms the system. I cannot begin to imagine what 4,000 a day looks like, so we are truly in a crisis."

[Also read: Obama's DHS Secretary Jeh Johnson: 'We are truly in a crisis' at southern border]

That is something Democrats in Congress will not admit. Perhaps they believe doing so would give a victory to Trump, which they cannot abide.

An expanded and strengthened border barrier would help in the long run. But in the immediate crisis, Trump realizes that the U.S. must change its policy of giving immediate and de facto permanent entry to virtually anyone requesting asylum. A large majority do not have a valid claim yet get to stay in the United States anyway.

"Democrats, working with Republicans in Congress, can fix the asylum and other loopholes quickly," Trump tweeted Monday. "We have a major National Emergency at our Border. GET IT DONE NOW!"

It could be done. But doing so would require recognizing the emergency at the border as real, not fake, and not manufactured. Can Washington do that?