意见反差巨大的美国选民11月6日星期二将投票选出新一届国会，同时对特朗普总统的执政做出中期评判。选举结果可能会改变华盛顿的权力平衡，影响到特朗普总统未来两年的执政。
国会所有的435个众议院席位和参议院100个席位当中的35个要改选，全美50州有36个举行州长选举。
民意调查显示民主党在争夺众议院控制权的竞争中占有优势。人们看好民主党会赢得更多众议院席位。他们需要增加23个席位就能成为众议院多数派。
共和党寄希望于特朗普总统的助选能帮助他们保持参议院51席比49席的微弱优势。面临中期选举改选的35个席位中，民主党人占有26席，共和党人占9席。
聚焦移民问题
在特朗普2016年赢得胜利的10个州，包括田纳西州，民主党要努力保住他们的联邦参议员席位。
特朗普总统最近在田纳西州查塔努加的一次集会上抨击了民主党的移民立场。
他说：“民主党人想邀请一批又一批的移民大军涌进我们的国家。我坚决不同意。没有任何国家会允许自己的边界被践踏。这是入侵。我不在乎他们说什么。我不在乎假新闻说什么。这是对我们国家的入侵。”
民主党阵营有包括前总统奥巴马在内的一些知名人士助选。奥巴马在他的家乡伊利诺伊的集会上告诉选民，特朗普为阻止移民大军向边界部署军队是“政治把戏”。
有几个州的提前投票人数众多，尤其在一般投票人数很难达到40%的中期选举。
特朗普是话题中心
民调显示民主党最关心的是医保和经济，共和党人则关注移民问题。
不过布鲁金斯研究所专家约翰·胡达克指出，很明显两党选民今年也看重特朗普总统。 他说：“这是一个想要把中期选举当作对他投票的总统，很大程度上因为他认为自己很受欢迎，一定会带着共和党人冲过终点线。”
特朗普总统在今年的选举中不仅在与民主党竞争，也要顶着历史潮流。华盛顿的两党政策中心专家约翰·福尔提埃尔说：“总体来说中期选举对总统的政党不利。我认为这次不会例外。民主党在众议院、州长和州议会选举中都会表现很好。”
维吉尼亚大学分析人士凯尔·康迪克指出，自1900年以来的29次中期选举中，除了1934年、1998年和2002年，所有的中期选举中总统的政党都丢失了一些众议院席位。
民主党人会出来投票吗
不过从历史来看在中期选举中共和党人会更积极参与投票。
盖洛普民调专家弗兰克·纽波特说，这对民主党人造成了压力，必须确保他们的支持者出来投票。
纽波特说：“在共和党人更有可能参加投票的情况之下，民主党人是否能调动支持者的积极性出来为他们的候选人投下一票呢？”
如果民主党能够获得足够席位夺回众议院多数，特朗普总统必须面对一个权力平衡改变的华盛顿。
民主党希望这是一次有重大改变的选举，让他们夺回众议院控制权，以及获得佛罗里达、俄亥俄和威斯康辛这些重要州的州长选举胜利。
共和党希望特朗普总统在最后阶段马不停蹄的助选活动能帮助他们维持甚至扩大在参议院的多数地位。
A sharply divided U.S. electorate is voting Tuesday to elect a new Congress and to render a midterm verdict on President Donald Trump. The results could shift the balance of power in Washington and alter the next two years of Trump’s presidency.
All 435 seats in the House of Representatives are at stake Tuesday, plus 35 of the 100 U.S. Senate seats and 36 of the 50 state governorships.
Public opinion polls and analysts suggest that opposition Democrats have an advantage in the battle for control of the House of Representatives. Democrats are favored to win more House seats than they currently have and they need an overall gain of 23 to retake the House majority.
Republicans are counting on President Trump to rally his supporters to help maintain their narrow 51 to 49 seat edge in the Senate. Of the 35 Senate seats at stake Tuesday, Democrats hold 26 and Republicans hold nine.
Immigration focus
Democrats are trying to hold 10 Senate seats in states where Trump prevailed in the 2016 election, including Tennessee.
Trump blasted Democrats over immigration during a recent rally in Chattanooga.
“Democrats want to invite caravan after caravan of illegal aliens to pour into our country. I don’t think so,” Trump said, invoking images of the caravan of Central American migrants moving through Mexico. “No nation can allow its borders to be overrun. And that is an invasion. I don’t care what they say. I don’t care what the fake media says. That is an invasion of our country.”
Democrats are getting some high-profile campaigners to help them including former President Barack Obama, who rallied voters in his home state of Illinois and told them Trump’s deployment of U.S. troops to the border in response to the caravan was a “political stunt.”
Early turnout has been huge in several states, especially for a midterm election when total voter turnout often struggles to reach 40 percent of eligible voters.
Trump a central issue
Polls show Democrats are most concerned with health care and the economy, with Republicans focused on immigration.
But Brookings Institution expert John Hudak said it is also clear that Trump is a major issue for both parties this year.
“This is a president who wants this midterm to be a referendum on him, largely because he thinks his own popularity is so great that it will carry Republicans across the finish line,” Hudak said.
But Trump is not only battling Democrats in this year’s election, he is also battling history.
“The big picture is that midterm elections go against the president’s party,” noted John Fortier of the Bipartisan Policy Center in Washington. “I think there will be no difference here. The Democrats will do quite well in the House of Representatives, in the governorships and state legislatures.”
University of Virginia analyst Kyle Kondik notes that in the 29 congressional midterm elections held since 1900, the president’s party has lost House seats in all but three — 1934, 1998 and 2002.
Will Democrats turn out?
Historically, though, Republicans are more reliable voters in midterm elections.
Gallup pollster Frank Newport said that puts pressure on Democrats to make sure their supporters get out and vote.
“Under the expectation that Republican voters typically are more likely to turn out, can Democrats energize people who identify with the Democratic Party to turn out and vote for their candidates?” Newport said.
If Democrats win enough House seats to reclaim the majority, Trump would face a shift in the balance of power in Washington.
Democrats are hoping for a wave election that would bring them control of the House and gubernatorial victories in key states like Florida, Ohio and Wisconsin.
Republicans are counting on Trump’s frenetic campaign pace in the final days to help them retain or even expand their narrow Senate majority.