I'm dubious about this prospect as well. After all, a lot of our Visas are targeted at getting "high skilled" immigrants to come into the country. So, just as much as the focus is on getting "low skilled" immigrants into the country for really difficult agricultural work (and these industries are begging for more immigrants to do this work), we see that our country also appreciates fleshing out "high skilled" work.
Undocumented immigration allows for certain labor violations. But the answer is to move towards a system of both yielding disincentives to immigrating illegally (nationwide eVerify) and creating a pathway to citizenship for those already here and better streamlining our legal immigration system to allow more immigrants into the country legally.
Support for both the present level of immigration and increasing it more than doubles the support for those who want to decrease it. We could break down what is understood to be "present level", but it stands to reason that these people would likely take a trade-off of higher legal immigration levels if it means stymying undocumented immigration. And, let's face it, those who want decreases in immigration are more likely to support Donald Trump than they are any Democrat. I think that the push would probably only have backlash, really, from those who would already be upset by the policy proposals of a Democratic President who replaced their favorite one.
On the flip side, there are a lot of things that are in place in our social infrastructure that require a lot of immigrants. As with most developed countries, our replacement level fertility has slowed down--especially among native born Americans. Social Security's viability has suffered because of a lot of things but those structural changes have been another driving factor in people saying that Social Security is going bankrupt. A good half of our overall economic growth is from population growth in the past. Now, we are at a place in our economy where every year-over-year GDP increase has to come from pure productivity gains. That's why we haven't been able to get above 3% annual growth for a while--and why it is unlikely to happen again. Our infrastructure is faltering because of sociopolitical forces domestically driving down fertility rates. We can either try to address those multi-variate sociopolitical factors to drive up the fertility rates (which, frankly, isn't going to be through laissez-faire policy that allows for wage stagnation, university costs to skyrocket out of reach for a lot of people, or allows for continued cost increases in child care) or we can take the easier route: increasing immigration.
The truth is that people who are scared of political change probably are right to be fearful of immigration. But they should also be scared of younger people who have a higher propensity to criticize capitalism and question whether or not socialism would be a better system. They should be concerned about the way that minority populations are growing faster to overtake, independent of immigration, of the majority population today. They should be concerned that, by millennial vote alone, Clinton won 49 out of 50 states in the United States. The only thing that doesn't change in our country is change. There will always be changing demographics, changing preferences, changing culture, and changing policy. Of course, your presumption is that 50,000,000 new immigrants would be eligible to vote immediately (they wouldn't be), that their opinions wouldn't be influenced by their environment in the United States while waiting to gain full citizenship status (which is unlikely), and that those immigrants would vote at 100% rates (which is highly unlikely, especially if they end up taking those lower paying jobs--as, statistically, we've seen people in these positions vote at much lower rates). Realistically, it could have an impact. But it would be in the long-term, not short-term, and it would be something that is probably going to either act, hopefully for conservatives and to the detriment of liberals, as a deterrent to continued liberalization of our politics or will only continue us down the path of liberalization of our politics. Either way, I'm dubious about the prospect of the idea that these people are going to change our political culture in a completely different way. Indeed, many people with authoritarian tendencies, tended towards Donald Trump in the previous election cycle. And, as we know, many of these people were native born Americans. I don't see many people fleeing from persecution being more damaging to democracy than voting for a candidate that praises dictators and ostracizes our allies, to the point where even the European Union has deemed us an adversary.
But it will also be a way to increase revenue. Not only will it continue to increase GDP (as I've stated, population increases are correlated, positively, with economic growth), but it gives us more tax payers that pay into these social systems. Indeed, we should be raising Visa limits for both "high skilled" and "low skilled" workers which will provide that kind of economic balance between the two kinds of immigrants. In short, I doubt that this is going to be so detrimental that we ought to be allowing people to die south of our border.
Ehh, I think that we probably won't see impeachment until support for it approaches closer to 50 percent. That might be a consequence of these other investigations that they are pursuing. If they can drive up the support for impeachment to start, the idea is that it will only continue upwards with further impeachment hearing. I think the idea of these other investigations is to see if there is a there there. That way, they can determine if there might be more information they can collect through impeachment proceedings. Then, and only then, can Democrats make a case to an American public that wanted to impeach their president that they tried and the Republican Senate took a partisan tack. That can be damaging. Heck, even with Bill Clinton, with the support for impeachment much lower, still hurt the Democrats in the next general election.
I don't see the Democratic base willing to punish Democrats, other in the primaries, with electing Republicans, who wouldn't have done anything in the face of this mounting evidence. I think that looking at the base for queues is probably not too terribly important. Indeed, I think that they will be even more fired up to get Donald Trump out of office in 2020 than they would be to get Mike Pence out. The idea is that not doing impeachment might have the same political effect as pursuing it as it continues to tie the Republican Party to Donald Trump and he remains perpetually unpopular.