Democrats need a net gain of four Senate seats for a majority, and the final polls give them a map to that majority that is clear in outline and uncertain in detail. They lead in five Republican held states, Texas, Kansas, Maine, Ohio and Alaska, with Iowa tied and Michigan, the Democratic held seat in the set, showing a wider lead. Four gains from that set would deliver a majority. Three gains would leave them short, unless they also hold every seat they already hold and win a tied state. The arithmetic is simple. The execution, state by state, is not.
Texas and Kansas are the symbolic gains. Texas has not elected a Democrat to the Senate since 1988, Kansas since 1932, and final polls put Talarico ahead of Paxton by 50 percent to 43 percent in Texas, and Hamilton ahead of Marshall by 49 percent to 44 percent in Kansas. Those leads, if they hold, would be historic breaks. But both leads sit close to or inside the margin of error in some polls, with YouGov finding Texas at 51 percent to 47 percent and Kansas at 50 percent to 49 percent, which means neither state can be counted as won before Tuesday.
Ohio and Maine are the steadier gains, if the polls are right. Brown leads Husted in Ohio by 49 percent to 44 percent in Times and Siena, and by 50 percent to 48 percent in YouGov. Maine shows a Democratic lead in the battleground set, though candidate name reporting varies between outlets. Alaska, with a lead within a 4.8 point margin on a sample of 610, is the least secure gain, and Iowa, virtually tied, is not a gain at all until counted. The path to four therefore requires winning at least four of Texas, Kansas, Ohio, Maine and Alaska, while holding Michigan and not losing any other seat.
The House path is separate
The House path is separate and, in some ways, simpler. Democrats need a net gain of three House seats, and national polls give them a lead of 51.5 percent to 43.1 percent in the generic ballot, with surveys showing leads of seven, ten and thirteen points. A national lead of that size, if it translates into seats, would deliver a House majority with room to spare. But House seats are won district by district, and a national lead can coexist with losses in specific districts where local candidates, local issues and turnout differ from the national mood. The House majority, like the Senate majority, will be decided by districts and states, not by national averages.
Cost of living and presidential approval frame both paths. Democrats hold a nine point advantage on cost of living across battleground states, and only 38 percent of likely voters in those states approve of President Donald Trump’s job performance. The Senate majority arithmetic therefore reflects a national mood that favours Democrats, but a Senate map that requires that mood to break through in Republican leaning states, where partisan loyalty is strong and where Election Day turnout has traditionally favoured Republicans.
What a split result would mean
A split result, Democratic House and Republican Senate, or vice versa, would produce divided government with different consequences. A Democratic Senate and House would allow legislation, confirmations and investigations to proceed without Republican obstruction. A split Congress would force negotiation on every bill, with the president’s veto power as a final check. Voters on Tuesday are therefore not only choosing individual senators and representatives. They are choosing the governing structure for the next two years, and the final polls suggest they are leaning toward a change, without yet guaranteeing it.
