Wouldn't it be simplest to just legalize the people who are here and at the same time also open up immigrant visas too?

This already happened in 1986.

"The Immigration Reform and Control Act legalized most undocumented immigrants who had arrived in the country prior to January 1, 1982. The act altered U.S. immigration law by making it illegal to knowingly hire illegal immigrants, and establishing financial and other penalties for companies that employed illegal immigrants."

"By splitting the H-2 visa category created by the Immigration and Nationality Act of 1952, the 1986 law created the H-2A visa and H-2B visa categories, for temporary agricultural and non-agricultural workers, respectively."

"Despite the passage of the act, the population of undocumented immigrants rose from 5 million in 1986 to 11.1 million in 2013."

https://en.wikipedia.org/wiki/Immigration_Reform_and_Control...

> Wouldn't it be simplest to just legalize the people who are here

I recently went down this rabbit hole a bit thinking this was the obvious solution and was surprised to learn that the Reagan administration legalized all illegal immigrants in the USA in 1986: https://en.wikipedia.org/wiki/Immigration_Reform_and_Control....

State control over employment and borders in the US is just too weak to prevent people coming over and so 30 years later this leads right back to the initial state.

> Wouldn't it be simplest to just legalize the people who are here and at the same time also open up immigrant visas too?

Any form of amnesty encourages the same behavior in the future.

How many and what kind of immigrant visas is an open question. There's definitely a need for more workers in some fields. Healthcare in particular could be well served by importing (even more) doctors from around the world.

What's not up for debate is whether we should be enforcing our immigration laws. If people different laws enforced, then get the laws changed. There's no unfairness to the current laws. And flooding the country with cheap labor hurts the lowest tiers of the populace the most.

It creates a huge moral hazard to reward those who illegally entered/overstayed visas