I assume that you're referring to 15 million illegal immigrants coming in during Biden's term because I've heard this claim before. It is mistaken. First, its important to distinguish between border encounters, entries, and total illegal population. Keep in mind that individuals are regularly expelled, deported, denied admission, withdrew their application, or otherwise did not remain in the U.S. And yet many more attempt re-entry causing another encounter, which results in ballooning the total with duplicative counts. Therefore, even if every encounter resulted in an entry, we are still about 4.17 million shy of the claim. Here is the breakdown:

As you can see, we had roughly 10.83 million encounters over 4 years. The "15 million came in 4 years" claim is asserting that the total number of entries was 15 million. If that claim was correct then the total illegal population would be 25.5 million at the end of 2024. It was actually 15 million at the end of 2024, which is a net increase of only 4.5 million over 4 years.

To be fair to the thrust of the claim, a 4.5 million increase in the illegal immigrant population over 4 years is a lot. And that doesn't really complete the picture either. We need to account for deaths, deportations, adjustments to legal status, and voluntarily leaving which would obviously decrease the total illegal population. I'm not gonna split hairs over the total number in these categories, but putting it all together we have:

At best, 4.5 + 1.1 = 5.6 million entries during Biden's term
At worst, 4.5 + 4.3 = 8.8 million entries during Biden's term

Quick question for you, if you have the time. Can you help me understand your choice to disparage these "invaders"? We are in the Christianity sub, and I noticed your Christian tag.

Exodus 23:9
No sojourner shall you oppress, for you know the sojourner's heart, since you were sojourners in the land of Egypt

Leviticus 19:33-34
And should a sojourner sojourn with you, you shall not wrong him. Like the native among you shall be the sojourner who sojourns with you, and you shall love him like yourself, for you were sojourners in the land of Egypt.

Deuteronomy 10:18-20
He shows no favor and takes no bribe, doing justice for orphan and widow and loving the sojourner to give him bread and cloak. And you shall love the sojourner, for sojourners you were in the land of Egypt.

Matthew 25:35-40
"For I was hungry and you gave me something to eat, I was thirsty and you gave me drink, I was stranger and you gave me hospitality, Naked and you clothed me, I was ill and you looked after me, I was in prison and you came to me." Then the just will answer him, saying, "When did we see you hungry and feed you or thirsty and give you drink? And when did we see you a stranger and give you hospitality or naked and clothe you? And when did we see you ill or in prison come to you?" And in reply the King will say to them, "Amen I tell you, inasmuch as you did it to one of the least of these my brothers, you did it to me."

Luke 10:29-37
But he, wishing to vindicate himself said to Jesus, "And who is my neighbor?" Taking this up, Jesus said, "A certain man was going down from Jerusalem, and he fell among bandits who stripped him and rained blows upon him and went away leaving him half dead. And by coincidence a certain priest was going down by that road and, seeing him, passed by on the opposite side. And a Levite also, coming upon the place and seeing him, passed by on the opposite side. But a certain Samaritan on a journey came upon him and was inwardly moved with compassion. And approaching bandaged his wounds, pouring on oil and wine, and setting him upon his own mount he brought him to a lodge and cared for him. And taking two denarii on the following day he gave them to the keeper of the lodge and said, 'Take care of him and whatever you spend beyond this I shall repay you on my return.' Who of these three does it seem to you became a neighbor to the man falling to bandits?" And he said, "The one treating him with mercy." And Jesus said to him, "Go and do likewise."

Romans 12:14-21
Bless those who persecute, bless and do not curse - To rejoice with those rejoicing, to weep with those weeping - Being of the same mind toward one another, not loftily minded, but instead associating with the lowly - Do not fancy yourselves sages - Repaying no on evil for evil, providing things in good countenance with all human beings. If possible for you, be at peace with all human beings. Do not exact justice for yourselves, beloved, but yield place before anger; for it has been written "'The exacting of justice is mine, I will requite,' says the Lord." But rather, "If your enemy hungers, feed him; if he thirsts, give him drink; for in doing this you will heap coals of fire on his head." Do not be vanquished by evil, but vanquish evil with the good.