Republican Mitt Romney leads President Barack Obama in Public Policy Polling’s latest survey of likely voters in Iowa by 49 percent to 48 percent. For Romney, that’s a big improvement since PPP polled Iowa in late September and a much better finding than yesterday’s poll from NBC/Wall Street Journal/Marist.

PPP’s new poll also suggests Iowa Supreme Court Justice David Wiggins might not be retained. More details are below.

UPDATE: On October 21, PPP released a different Iowa poll conducted during the same period, which showed Obama leading Romney by 49 percent to 48 percent. I’ve added excerpts from that polling memo at the end of this post.

PPP surveyed 869 Iowa likely voters between October 17 and 19, producing a margin of error of plus or minus 3.3 percent. PPP’s Tom Jensen summarized the highlights here; the full polling memo is here (pdf). Romney’s “net favorability has improved 16 points from a -15 spread at 40/55 on our last [Iowa] poll to now 48/47.” In addition, Iowa likely voters believe Romney would better handle the economy by 49 percent to 45 percent.

Other notes from Jensen:

-Obama has opened up a huge lead among early voters, 66-32. Those folks represent 31% of the electorate. But with the 69% of folks who have yet to cast their ballots, Romney leads 56-39.

-Obama is actually winning independent voters 46/42, but Republicans have built a registration advantage in the state over the last four years and Romney’s small lead is largely a reflection of that.

-Obama is up 60/38 with voters under 65, but he’s losing every other age group.

The NBC/WSJ/Marist poll was better for Obama across the board, though both surveys found a roughly 2:1 lead for the president among Iowans who have already voted. For that to be true, Obama would have to have a substantial advantage among the no-party voters who have requested absentee ballots.

One key difference between NBC/WSJ/Marist and today’s poll is that PPP’s likely voter sample contains more Republicans than Democrats: 38 percent Republicans, 34 percent Democrats, and just 27 percent no-party voters.

In the 2008 presidential election, 1,528,715 Iowans cast ballots: 568,377 Democrats (37 percent), 491,342 Republicans (32 percent), and 467,762 no-party voters (a little below 31 percent). But at that time, Democrats had a voter registration advantage in Iowa as well as an “enthusiasm gap.” Now there are more registered Iowa Republicans than Democrats, although independents are still a plurality of the electorate.

Some 45 percent of PPP’s respondents said they would vote Republican for the state legislature, while 43 percent said they would vote Democratic. That’s not a large enough margin to draw any conclusions about Democrats’ chances to hold their Iowa Senate majority.

Jensen observed,

Iowa’s Supreme Court retention election looks like it could be pretty close. Right now 37% of voters say they plan to keep David Wiggins in office, while 43% say they’re inclined to remove him. With 20% of voters still undecided it could go either way, but Republicans (65%) are more committed to removing him right now than Democrats (59%) are to keeping him.

Looking ahead to 2014 Terry Branstad has the best approval numbers we’ve found for him since he took office with 51% of voters happy with the job he’s doing to 33% who disapprove. He leads a generic Democrat 53 – 34. Tom Harkin could be vulnerable in 2014. His approval numbers are split down the middle at 40% and he leads a generic Republican foe only 45-42. Chuck Grassley continues to be the most popular politician in the state with a 54/28 approval rating.

I expect both Branstad and Harkin to seek re-election in 2014. Harkin’s approval numbers are always lower than Grassley’s, so no surprises there. The question is whether Republicans will recruit a strong challenger for the U.S. Senate race, or someone on the level of the three men who ran against Harkin in 2008. They weren’t an impressive bunch, to put it mildly. The Iowa GOP didn’t invest much in the eventual Senate nominee, Christopher Reed.

PPP’s numbers on the retention vote are worse for Wiggins than either of the two previous published polls on this race. Supporters of keeping Wiggins on the Iowa Supreme Court need to work on those undecided voters, because I suspect the typical “No Wiggins” voter is more enthusiastic than the typical Iowan voting yes. It’s worth noting that even when there is no controversy surrounding the state Supreme Court, roughly 20 percent of Iowans who cast ballots tend to vote against retaining all judges.

OCTOBER 21 UPDATE: Health Care for America Now commissioned the latest PPP poll of Iowa. The pollster interviewed 660 likely voters on October 18 and 19 (overlapping with the other polling period), producing a margin of error of plus or minus 3.8 percent. The question wording was different from the poll PPP released on Friday, and I suspect that may have influenced the findings. From Tom Jensen’s polling memo (pdf):

50% of Iowa voters say that they trust Obama more to stand up for the middle class, compared to 47% of voters who pick Romney on that front.

Voters also trust Obama a lot more than Romney to make sure the wealthiest Americans pay their fair share of taxes. 50% of Iowans say they have more faith in Obama than Romney on that front, including a 49/41 spread with independent voters.

Obama’s banked a large lead in Iowa among folks who have already voted, getting 64% to 35% for Mitt Romney. That means Romney has a big deficit to overcome in the state over the next two weeks. Obama’s small overall advantage also owes to strong support from women (53/44) and young voters (55/45). Romney is ahead 53/45 with men and 54/42 with those who have yet to cast their ballots.

That’s three polls showing a 2:1 advantage for Obama among early Iowa voters.

PPP’s survey for Health Care for America Now didn’t show any advantage for the president on which candidate “do you trust more to protect Medicare” (47 percent for both candidates) or which candidate “do you trust more to keep tax rates fair for the middle class” (49 percent Romney, 48 percent Obama).