中期选举选前预测汇总：各模型一致看好民主党夺回众议院、参议院归属仍胶着
2026年中期选举将于11月3日（周二）举行，众议院全部435个席位改选。选前最后阶段汇总的民调平均、预测模型与预测市场方向一致：民主党被看好夺回众议院，参议院归属则明显更接近。
众议院方面，RealClearPolling 的国会通用选票平均显示民主党领先共和党8.3个百分点（统计期为9月28日至10月19日）；NPR、PBS News 与 Marist 10月27日公布的民调显示，在可能选民中民主党以52%对44%领先。Decision Desk HQ 的预测模型（10月29日更新）给出民主党80%的概率夺回众议院，并预计其赢得238个席位；Cook Political Report 预计民主党净增12至22个席位，即总数落在227至237席之间，其10月23日的评级中民主党已在218个席位上被看好。预测市场方面，Polymarket US 与 Kalshi 给民主党赢得众议院的概率分别为93%与92%。
参议院方面，共和党目前以53席对47席占多数，民主党需要净增4个席位才能取得多数（50对50平局时由共和党籍副总统投下决定票）。Decision Desk HQ 的模型给出民主党60%的概率赢得参议院、预计52个席位；Polymarket US 与 Kalshi 均给出68%。Cook Political Report 列出7场势均力敌的参议员选举，其中6场是共和党现任席位，1场是民主党在 Michigan 的席位，并预计民主党参议员席位净增2至6席。
需要说明的是，通用选票衡量的是全国层面的政党偏好，众议院结果由435个选区逐区决定，全国领先幅度摊到各区后可能收窄；预测市场价格反映的是交易者的下注，而非对选民的抽样调查。各方最终结果以11月3日投票与计票为准。
Final Midterm Forecasts: Every Model Favors Democrats for the House, While the Senate Stays Close
The 2026 midterm elections take place on Tuesday, November 3, with all 435 House seats up for election. In the final stretch, polling averages, forecast models and prediction markets agree on direction while differing on size: Democrats are favored to regain the House, while the Senate is much closer in every source.
For the House, RealClearPolling's generic congressional ballot average has Democrats up 8.3 points nationally (covering September 28 to October 19), and the NPR/PBS News/Marist poll released October 27 put Democrats ahead 52% to 44% among likely voters. Decision Desk HQ's forecast model, updated October 29, gives Democrats an 80% chance of winning the House and projects 238 Democratic seats. The Cook Political Report projects a Democratic gain of 12 to 22 seats, putting the party at 227 to 237 seats; in its October 23 ratings, Democrats were already favored in the 218 seats needed for a majority. On prediction markets, Polymarket US priced Democrats at 93% and Kalshi at 92% to win the House, as of October 31.
For the Senate, Republicans hold 53 seats to 47 for Democrats and the independents who caucus with them; because a 50-50 tie is broken by the Republican vice president, Democrats need a net gain of four seats for a majority. Decision Desk HQ's model gives Democrats a 60% chance of taking the Senate and projects 52 seats, while Polymarket US and Kalshi both price the chance at 68%. The Cook Political Report lists seven Senate races as Toss Ups — six Republican-held seats and one Democratic-held seat in Michigan — and projects Democratic gains of two to six seats.
The generic ballot measures national party preference without naming candidates; House control is decided district by district, so a wide national margin can shrink into a modest majority. Prediction market prices reflect traders' bets rather than surveyed voters. The outcome will be settled by the votes cast and counted on November 3.
来源：GSM·美国（原文链接）
图片来源：图：位于华盛顿的美国国会大厦西立面（资料图）。Architect of the Capitol 摄，公共领域，经 Wikimedia Commons。 / The west front of the U.S. Capitol in Washington (file photo). Photo by the Architect of the Capitol, public domain, via Wikimedia Commons.
