Transcript for Early voting begins in Nevada
Next, to politics and the race for 2020. Early voting now under way in Nevada, a key caucus state that is next up. The democratic candidates zeroing in on that western contest and gearing up for yet another debate. Here's ABC's Rachel Scott. Reporter: Tonight, the democratic race for president swings west. Candidates flooding the state of Nevada, with the caucuses here just one week away. Senator Bernie Sanders bringing his supporters straight to the polls, leading a March as early voting gets under way. Senator Bernie Sanders, riding a wave of enthusiasm after his New Hampshire victory, brushing off criticism from union leaders who are slamming his medicare for all proposal. Senator, any concern about possibly losing union votes? Well, were you just watching this? Reporter: Yes, I was, Okay, I never been to -- we had about 700 people marching in to vote. We are feeling absolutely great. Reporter: Former vice president Joe Biden, hoping for a boost, says he has a shot at placing top two in Nevada. 99% of the African-American vote hasn't spoken yet, and 99% of the Latino vote hasn't spoken yet. Reporter: Nevada is the first test to see which candidates can appeal to minority voters. Why should they give your campaign a chance? Well, I need to get to know them, because my name I.D. Wasn't very high. My bank account, not as big. Reporter: Though he's skipping the state, former New York City mayor Michael Bloomberg is closing in on the debate stage here. As his profile in this race grows, so does the scrutiny around his past. Just this week, Bloomberg taking heat for his previous comments on racial discrimination and lending, a practice known as redlining, and stop and frisk. I should have acted sooner and I should have stopped it and I didn't. And I apologized for that. Reporter: "The Washington post reporting on allegations of sexism at his company that have dogged Bloomberg for years, as reported by ABC news. His spokesperson responding, saying, "Mike simply does not tolerate any kind of discrimination or harassment." And "The drudge report" claiming Bloomberg is considering announcing 2016 democratic nominee Hillary Clinton as his running mate. His campaign telling ABC news can't, "We are focused on the primary and the debate, not V.P. Speculations." Voters are already in line as early voting takes off. The Nevada democratic party has revamped its strategy after the chaos during the Iowa caucuses, scrapping its plan to use an app and instead using a new tool to better calculate the results. Tom? That caucus just one week away. Rachel, thank you.
This transcript has been automatically generated and may not be 100% accurate.