U.S. Senator Chuck Grassley is outperforming the top of the Republican ticket and leads former Lieutenant Governor Patty Judge by 53 percent to 36 percent in the latest Iowa poll by Selzer & Co for the Des Moines Register and Mediacom. The Register’s William Petroski wrote up the key findings:

The Iowa Poll shows Grassley has broad support, leading Judge among all groups tested except for four: Democrats, Hillary Clinton supporters, former Bernie Sanders supporters and people who identify with no religion. Among political independents, Grassley leads Judge 54 percent to 30 percent. He leads among men and women and among all age, income and education groups.

Grassley’s job approval rating — with 56 approving and 30 percent disapproving among all adults, not just likely voters — is identical to where it stood in September 2010, before he cruised to victory that November, defeating Democrat Roxanne Conlin by 31 percentage points.

Among the same 642 “likely voter” respondents, Donald Trump leads Hillary Clinton by just 43 percent to 39 percent.

Selzer’s poll was in the field before the release of a 2005 videotape in which Trump bragged about assaulting women he finds attractive. Democrats have blasted Grassley for condemning Trump’s comments but urging Republicans to stick with the GOP ticket, because of the election’s likely impact on the U.S. Supreme Court. I doubt the Trump tape will affect Grassley’s re-election numbers, though.

Iowa Republicans have been spiking the football on this race for some time. Yesterday the Twitter accounts of Grassley’s campaign and campaign manager Bob Haus directed followers to the liberal Daily Kos website, where IA-Sen is now listed as safe Republican. Various other election forecasters see the race the same way.

Many Iowans who preferred State Senator Rob Hogg for U.S. Senate, as I did, have privately expressed frustration that the Democratic Senatorial Campaign Committee has spent almost no money here, after intervening in the Democratic primary to recruit and promote Judge. The DSCC’s tactical choice is understandable, because more than half a dozen other Senate seats are better pickup opportunities than Iowa’s. But I do wish they’d stayed out of the primary. Although Judge had higher name recognition, I never did see evidence that she was in a position to make this race more competitive than Hogg. She has held relatively few public events around the state since winning the nomination. Hogg would have been much a more active campaigner, which might have helped our down-ballot candidates.

Was Grassley ever truly vulnerable? Beating a six-term senator was always going to be hard in a state that generally re-elects its incumbents. Grassley has been able to spend millions more dollars on tv ads than any challenger could have managed. (I enclose below his latest positive spot.) His support took a hit from his handling of the Supreme Court vacancy, which inspired the DSCC to recruit Judge. I would guess that refusing to hold confirmation hearings for Judge Merrick Garland is the main reason Grassley’s leading by “only” 17 points now. Selzer’s polls for the Des Moines Register in September and October 2010 showed him 31 points ahead of Roxanne Conlin.

The Grassley campaign’s latest 30-second positive ad, “RUN,” is narrated by the senator’s wife Barbara Grassley.