Newsweek’s latest polling shows John McCain pulling into a tie with Barack Obama at 46%, despite a small imbalance in the sample towards Democrats.  McCain has gained 5 points since the last Newsweek poll in July, and more importantly, has surpassed Obama in voter enthusiasm:

With 53 days until Election Day, John McCain has pulled even with Barack Obama in the latest NEWSWEEK Poll. Buoyed by the Republican convention and overwhelming partisan enthusiasm for his choice of Sarah Palin as his running mate, McCain is now tied with Obama among registered voters nationwide, 46 percent to 46 percent.

Two weeks of all-Sarah Palin-all-the-time media coverage, and the McCain bounce in national and battleground state polls, has spurred Democratic anxieties that despite President Bush’s dismal approval ratings, the party might be squandering the chance to take advantage and reclaim the White House. But NEWSWEEK’s Poll suggests the race is very much still in play. McCain’s current level of support, after all, is up just 5 points from July, before either party’s nominating convention, when Obama led McCain 44 to 41 percent.

Perhaps more troubling for the Obama campaign than the overall head-to-head numbers, however, is the dramatic hardening of McCain’s support suggested in the poll. In July, only 39 percent of McCain voters said they supported McCain strongly. By contrast, 71 percent now say they strongly support the Republican nominee. Obama, meanwhile, has seen support increase from his voters, as well, but far less dramatically—67 percent now say they support him strongly, compared to 61 percent in July. Enthusiastic support will prove crucial to both parties in a close election, as voters are more likely to turn out for, give money to and volunteer on behalf of candidates they firmly back.

It’s important to note that Newsweek polls for registered voters, not likely voters.  Most of the polling we will see from now until the election will focus on likely voters, and it’s unclear why Newsweek didn’t try drilling down for the more predictive sample.  Perhaps they hoped to get better news.

That may explain their satisfaction with a survey that only represents Republicans at 27%, with Democrats at 35% in the overall sample, with a 31-37 split respectively among registered voters.  That’s off slightly from the latest Rasmussen party identification numbers, which show a 33-38 split, meaning that Newsweek oversampled independents.  It’s not as large a difference as seen in CBS or previous Newsweek polling, but it will have a small effect on the predictive value of the poll.   Given the pronounced shift in the Congressional balloting polls in recent weeks, it seems likely that party identification may be even closer than the five-point spread shown from August.

Meanwhile, Rasmussen has a promising shift in their Electoral College projections:

New state polling from Missouri has helped move that state from from “Leans Republican” to “Likely Republican” in the Rasmussen Reports Balance of Power Calculator. With this change, McCain now leads in states with 200 Electoral College votes while Obama is ahead in states with 193 Electoral College votes. When “leaners” are included, it’s Obama 259, McCain 247.

Currently, states with 124 Electoral College votes are leaning slightly in one way or the other. Four states with a total of 32 votes — Colorado, Nevada, New Mexico, and Virginia — are pure toss-ups.

This is the first time McCain has led in this calculation, I believe.  All of the movement in the last week has come from six states traveling in McCain’s direction.  The four pure toss-ups, though, include three states Bush won in 2004, and are must-wins for McCain.  Iowa is still in the leans-Dem category, but some important states for Obama still remain in that category as well, including Pennsylvania, Michigan, and Washington — none of which Obama can afford to lose.

The trends show McCain seizing the momentum in this race.