Transcript for Record total voter turnout projected for 2018 midterm election

And we begin with the midterms, of course, and the exit poll results already coming in right now. So many races razor thin tonight. Massive turnout coast to coast, look at this line inside a gym in Georgia. In Houston, look at this. Lines out the door. And in St. Charles county, Missouri, lined up since early this morning. The first exit polls just in, and these are preliminary results tonight. Voters were asked, do you approve of the job president trump is doing? 44% said they approve, 55% said they disapprove. Did they vote today to send the president a message? Here's what they said. 26% said they voted to show their support, 38% said they voted to show their opposition to the president. And 33% said the president did not figure into their vote. We know so many issues in these state races were local. In fact, look at this tonight. When asked which one of these four issues is most important, health care by far topped the list at 41%, immigration, 23%. Followed by the economy and gun policy. So, let's get right to our chief national correspondent Matt Gutman and our team across the country tonight. Matt is in Santa Ana, California. Matt, I know they're processing the bat lots right behind you tonight? Reporter: That's right. They are expecting 800,000 ballots to go through this facility. The fifth-biggest in the country. The supervisor here tells me voter turnout has been so intense that people coming to vote in person have come out in greater numbers than they have in any presidential election, David. And that's one reason we're seeing lines of 90 minutes or more just outside the door here. They started lining up at dawn, in high school gyms in doylestown, Pennsylvania, parking garages in Atlanta, where people waited more than three hours to vote. In Knox county, Tennessee, the power went out, so poll workers pulled out their flashlights, citizens voting in the dark. Total turnout projected to top 100 million, a record for a midterm election. Driving the enthusiasm? President trump. So many voters showing up today to send him a message. Thank you so much. Reporter: In Missouri, Claire Mccaskill, one of ten vulnerable Democrat senators running for re-election in states trump won. ABC's Deborah Roberts is there, speaking with voters. Was your vote today about Missouri or about the president? Both. I cannot stand the president. I think he's just a faker and a liar and I hope he gets impeached. Reporter: Mccaskill's opponent, Josh Hawley, a strong trump ally, which means a lot to Pamela Meyer, whose key issue is immigration. So what do you want to say to the president about your vote today? Well, I love president trump. What can I say? He is the first president in years that's actually trying to do everything he said he would do. Reporter: In Texas, senator Ted Cruz among the most vulnerable Republicans. Beto O'rourke hoping to pull off the night's biggest upset. We're going to do this together. We just do not care about the differences between us right now. Reporter: At the polling place, O'rourke meeting 77-year-old Pamela, who grew emotional in this video now widely shared. We think he's pretty important. And we're honored that he was here. Why is he so important? Because he represents everything Donald Trump isn't. Reporter: In Florida, where folks today lined up around the block, the president a major factor in the racially-charged race for governor. Democrat Andrew Gillum versus Republican Ron Desantis. Thank you, sir. Rooting for you today, sir. Thank you, appreciate it. Reporter: ABC's whit Johnson is outside a polling place in Tallahassee. You voting for Gillum, you're also voting against president trump? Absolutely. I couldn't be more adamant about that. Reporter: But steps away, Connie jokisch, who came to vote straight from her overnight shift as a nurse, there to support one man -- the president. My brother-in-law has a job he hasn't had in three years, my brother has a job he hadn't had in five years. You know, they're happy. You know, this wouldn't have happened without trump, I don't think. Reporter: In Georgia tonight, Stacey Abrams looking to make history by becoming the nation's first female African-American governor. She is counting on high turnout among black voters like Tyler Cummings, who spoke to our Steve osunsami. What does it mean if Stacey Abrams wins tonight? Honestly, it means a lot to me, being an African-American individual, just to have someone being in the office that is African-American, as a woman. Reporter: Abrams' Republican opponent, Brian Kemp, has Donald Trump on his side. Abrams had Oprah, one of many celebrities making their voices heard this year. Taylor Swift, coming off the political sidelines, today urging young voters to turn out. I promise you it feels so wonderful to exercise that right that you have. Reporter: The big question tonight -- did they listen? Matt Gutman and our team out all across the country tonight. Matt back with us live, and Matt, our ballot watch team tracking polling stations across the country. Are we seeing any problems tonight? Reporter: There have been scattered problems, David. In North Carolina, the board of elections there says that ten poming stations reported problems with their vote counting machines. Apparently caused by humidity. So, some of those ballots are being stored in emergency bins until they can be counted. Also, in Johnson county, Indiana, just south of Indianapolis, apparently some machines broke during check-in, making it difficult to get people in, causing those delays that you see, and those long lines. Now, one voter protection group tells us that 24,000 people have called its hotline with problems and with questions. Much higher than in 2014, but David, given the size and scale of the voter turnout today, it's not that surprising. David? Matt Gutman leading us off tonight. Thank you so much.

This transcript has been automatically generated and may not be 100% accurate.