Model narrows New Mexico Senate range, lifting Lujan to 99 in 100

Our model now gives Democratic incumbent Ben Ray Lujan a 99 in 100 chance of winning the New Mexico Senate race. In the previous run, on August 25 at 10:03 a.m. ET, it gave him 90 percent. That is a move of nine points toward the Democrat over seven days.

The projected margin did not move with it. Our mean margin is D+14.9, against D+15.1 in the earlier run. What changed is the spread around that figure. A week ago our 5th-to-95th percentile range ran from R+4.2 to D+34.2, wide enough to include Republican Larry Marker winning. It now runs from D+4.4 to D+25.4. Narrower uncertainty around a stable central estimate is what drives a probability from 90 to 99 without changing the expected result.

One poll of the race arrived between the two runs. Research & Polling Inc., for the Albuquerque Journal, surveyed 516 likely voters from August 21 to 28 and found Lujan at 53 percent and Marker at 38 percent. That result sits close to our mean margin rather than pulling against it, which is consistent with a tightening interval. We cannot separate the poll's contribution from other inputs in this run, so we do not attribute the full nine points to it.

The national picture behind the race is closer. Our generic-ballot average, built from 26 polls over a 45-day window, stands at D+6.5. On Senate control our model splits almost evenly: a 50 percent chance Democrats win a majority against 49 percent for Republicans, with a mean of 50.3 Democratic seats. Democrats need 51 seats and Republicans 50, because the vice president is a Republican and a 50-50 tie goes to the Republicans. New Mexico is one of the safer seats in that arithmetic, not one of the ones deciding it.