Well I can give two American cents here.

I don't defend illegal immigration, I take issue with today's immigration laws.

I view our current immigration problems as an obvious side effect of welfare programs - creating financial incentives to physically be in the country means the government budget is a blank check and people have a reason to move here other than the hope of making a better life for themselves.

In my view, those immigration problems should be a sign that our welfare programs can't function without strong borders and heavily controlled immigration. We can't seem to solve immigration management, and until we do we should abandon the welfare programs and accept that people will move here if they want to.

Edit: I can also come at this from a fundamental rights angle. I am a strong believer in individual rights and don't believe that I have the right to decide who can live here.

They say "illegal immigration" in polite company, but they really mean non-white immigrants. They're also openly talking about revoking citizenships of legal immigrants. The right wing is seeking a rascist/fascist solution to a heavily exaggerated issue.

Because it's largely impossible to do it legally, with wait times sometimes being measured in decades.

The only difference between a legal and an illegal migrant is paperwork. If the paperwork route was a viable alternative, nobody would risk their lives crossing a river or a giant desert to do it illegally.

I take issue with the proposition. Not wanting to partake in building a machine that's going to be used by the government to hunt down "undesirables" isn't "defending illegal immigration".

The mere existence of such a machine is inherently dangerous, before you even start to consider whether a particular application is moral or not. Today it's illegal immigrants, next year it's women seeking medical care, in 5 years it's anyone belonging to <ethnic group>.

Also not American.

Some hire the illegal immigrants, and many benefit from the lower prices this brings.

The game theoretic payoff varies a lot depending on which specific interest and timescale you have, including from the countries the migrants come from who probably don't want their moderately capable citizens — above average but not by enough to do it legally — leaving, and wose: getting badly paid jobs so they can't send much cash back home.

I would expect the answer to mostly lie with what decides what "legal" is. If you view the current policies to be unreasonable, then immigration in defiance of those policies is defensible. Such arguments are usually coupled with gestures towards how we already rely on such immigration for our economy.

America is a land of immigrants. To say that the immigrants who got here earlier won’t let the immigrants who try to come later is against US values.

On a practical level, immigration is fundamental to the success of the US economy and is helping the US avoid the inverted pyramid demographic problem faced in many other countries like Japan.

The US economy depends on illegal immigrant labor - who do you think does all the picking in the Central Valley (CA)? But by restricting the path to immigration we exploit that labor since those people have no rights (just a step up from slavery).

I’m against illegal immigration not because I want them gone, like Trump, but because I believe we should allow them to immigrate legally instead of exploiting them.