Transcript for Trump ramps up fear rhetoric as midterm elections near

begin with the midterm elections just four days to go. Early voting is through the roof. More than 27 million votes cast so far. That's already 7 million more than in 2014 and social media is in overdrive. These are the most tweeted about midterms ever. Enthusiasm engagement appear to be at a record high. President trump trying to rally his base by raising fears about immigrants. ABC's senior white house correspondent Cecilia Vega is here with the latest. Good morning. Reporter: Good morning. The president is using words like national crisis and invasion to describe immigration in this country, even though that is not actually reality but this is his election strategy and by our count he's used hard-line immigration rhetoric nearly every day for the past three weeks. President trump's closing argument a doomsday scenario in which America is overrun by undocumented immigrants. If you don't want America to be overrun, you better vote Republican. Reporter: He is ramping up rhetoric using fear from the campaign trail -- These courageous Americans did not shed their blood, sweat and tears so that we could sit at home while others rye to erase their legacy, tear down our history and destroy our heritage. Reporter: -- To the Roosevelt room of the white house. This is not an innocent group of people. They've injured, attacked. Reporter: Even though the migrants, many poor and fleeing violence, are still about 900 miles from the border, and Mexican officials say the number is dwindling by the day. That is not stopping the president. He's now promising a new executive order to crack down on asylum seekers, a move sure to trigger legal challenges. He wants to potentially detain families indefinitely. We're putting up massive cities of tents. Reporter: The aclu issuing this statement, quote, if he plans at some point to prohibit from applying for asylum between the ports of entry that plan is illegal and those 15,000 troops the president says he'll send to the border, he now says they would fire their weapons at the caravan if migrants throw rocks. Envision them firing upon any of these people? I hope not. It's the military. I hope there won't be that but I will tell you this, anybody theying stone, rock, we will consider that a firearm. Because there's not much difference. They want to throw rocks at our military, our military fights back. We're going to consider and I told them consider it a rifle. Reporter: Retired general martin Dempsey saying of that troop deployment, our men and women in uniform are better trained, better equipped and better led so they meet any threat with confidence. A wasteful deployment of overstretched soldiers and Marines would be made much worse if they use force disproportional to the threat they face. They won't. Another false claim over his controversial zero tolerance policy separating families at the border, the president says it's all president Obama's fault. Here's the reality. Families under president Obama were separated because the parents were tied to saoirse Ronan crimes like drug trafficking. Under the trump administration crossing the border was crime enough and there are still 200 children in custody today. Cecilia, as you point out the president talked about it every day for the last few weeks. Throwing out new proposals every day. We have laws from prohibiting the military from being involved in enforcement action. It's not clear the military would be in any position to fire if there was any kind of violence. It's not clear if the Pentagon was ready for this. He wants as many as 15,000 troops on the border. The Pentagon says there will be up to 8,000 troops and firing on migrants seems to be at odds with what the Pentagon is saying. They're saying -- they're emphasizing the military will be there in a support role so who knows. Far from the border. Wouldn't even -- Building tents. Cecilia Vega, thanks very much. In this intense fight to the

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