| By Henry Olsen, senior fellow, Ethics and Public Policy Center Democrats have polling leads in most battleground Senate races, according to RealClearPolitics averages. Does that make them the favorites to win the majority? That depends more on the level of their support than on how much they’re ahead. Most polling analysis leans heavily on the lead a candidate holds going into Election Day. A candidate with a two-point lead, for example, is likelier to be considered a favorite than one who leads by under a point. But this approach overlooks a key factor: the absolute share of the vote a polling average says the candidate has. Consider Hillary Clinton’s 2016 polling. The Democratic presidential nominee’s margin over Donald Trump, her Republican opponent, rose and shrank during the last three months of the race, but that was mostly because Trump’s support fluctuated. Clinton’s lead grew from 3.2 percentage points on Oct. 8 to more than seven points on Oct. 17 primarily because Trump’s share of the vote declined. From Oct. 19 onward, polling found that Clinton’s support remained between 44.7 and 45.7 percent even as her lead ranged from more than six points to as little as 1.9. That was a clear tell that uncertain Republicans and independents would decide the race, and there was always a strong possibility they would break late for Trump. Despite all of Trump’s challenges, Clinton was not making the sale. Voters who didn’t care for Trump but tended to lean Republican on policy would decide who prevailed. This is the situation most Democratic Senate candidates are in today. The states that will determine the Senate majority are mostly heavily Republican, including Alaska, Iowa, Kansas, Texas and Ohio. If Republicans win four of those five, they will retain control because of Vice President JD Vance’s tiebreaking vote — even if they lose tight contests in much bluer Maine and Michigan. As in 2016, wavering Republicans and independents are the key voters in this year’s red battlegrounds. Democrats can stream to the polls all they want, and some early-voting data suggest they are. (It’s always wise to be cautious about drawing conclusions about early-voting numbers.) But it won’t be enough if Republican-leaning voters ultimately come home to the GOP. Because of all this, to truly be considered favorites, Democrats need to be leading by two or more points on election eve and be at or above 48 percent support. Fall short of either mark, and the race could easily flip the other way on just a small polling error or a late return by right-leaning voters to past patterns. This is one reason state Rep. James Talarico, the Democratic Senate nominee in Texas, looks stronger today than he did in late September, even though his lead is a little smaller. Talarico leads Republican Ken Paxton, the state attorney general, by 2.2 percentage points in the most recent RCP average. That’s down from 2.9 points on Sept. 30, but Talarico’s vote share is up nearly a point, sitting at 48.5 percent. If those numbers are accurate, Paxton would have to win about 70 percent of undecideds to pull even. That’s a tall order. However, in Ohio, former senator Sherrod Brown, a Democrat, appears to be in a weaker position even though his lead over GOP Sen. Jon Husted is a nearly identical 2.4 points. Brown’s support averages 47.1 percent and Husted is at 44.7, which suggests about 8 percent of voters are undecided. If Husted can win these voters by about a 5-3 ratio, a less daunting task than the one Paxton faces, it’s anyone’s race. This approach also explains why the smart money remains on Republican Sen. Roger Marshall to win reelection in Kansas, despite his being in an effective tie with Democrat Adam Hamilton. Marshall’s polling lead is a razor-thin 0.3 points, but Hamilton has only 45.7 percent support. It’s much likelier that the remaining voters in the ruby-red state break to Marshall than to Hamilton. To rate Hamilton the favorite, I would need to see him pass Marshall and increase his support to at least 48 percent. The Democrat in the Alaska Senate race easily clears that second bar, giving her a good chance to win despite a lead that is below the first one. Former Alaska congresswoman Mary Peltola is ahead of Republican Sen. Dan Sullivan by just 1.2 points, but she has 49.4 percent support in the most recent polling average. On the surface, Sullivan doesn’t appear to be in a very deep hole, but the sides of it are steep. Republicans will note that polling error could obliterate those small leads, but no state polling average diverged from the final result by more than 3.2 percentage points in 2024’s competitive Senate races. The miss was much higher in 2022, but it uniformly favored Democrats. This recent history doesn’t suggest there’s a consistent, pro-Democratic polling bias in contested Senate races. Polls are only snapshots in time, and there are still two weeks to go. If many Democratic candidates for Senate are leading by less than two percentage points while getting 47 percent in the final averages, election night is going to be a doozy. But if they’ve cleared the magic plus-two and 48 percent marks, it will be a happy night for Team Blue. Poll watchPresidential job approval is a key signal ahead of the midterms. But overall job approval doesn’t tell the whole story, and many aggregators wind up overestimating Trump’s political weakness. Margin of Victory is tracking a better indicator: approval among registered and likely voters. As Election Day nears, things are getting worse for Republicans. | 
