By Mark Willen, Senior Political Editor November 2, 2008 The longest, most unpredictable and most frenetic of presidential campaigns in quite a while is finally coming to a close. The last few days have been as wild as ever -- the candidates have spent millions of dollars on advertising in an unusually high number of states, they've crisscrossed the country, hitting half a dozen states or more in a single day and we've been hit with an unprecedented number of polls to sort through. But as we study the closing events, we don't see that the underlying dynamic of the race has changed very much.That's why we are leaving our electoral map the way it stood a week ago, with Democrat Barack Obama holding a meaningful lead in 24 states and the District of Columbia, which together would give him 291 electoral votes, 21 more than he needs to take the White House. McCain leads in 21 states with 163 electoral votes, with the remaining fivs (84 electoral votes) up for grabs. Unless the polls have totally misjudged the electorate, Obama seems certain to win the popular vote. Of 11 national polls taken during the Wednesday to Saturday period, Obama tops the magical 50% mark in all but two -- one by Fox News and one by Investors Business Daily, which both use a turnout model that predicts more Republican voters than other models. Even in those two polls, Obama leads, but he's shy of the 50% mark, meaning if McCain grabs most of the undecided, he could win the popular vote. The average of the polls, as calculated by RealClearPolitics, has Obama leading 50.5% to 44.2%, and the Sunday ABC/Washington Post tracking poll found that more than 50% said they "definitely" will vote for Obama. If he does top 50%, he will be the first Democrat to do so since Jimmy Carter in 1976. Bill Clinton won in 1992 and 1996 with 43% and 49%, respectively, aided by the third party runs of Ross Perot. In looking at the latest state polls, we see some tightening in Pennsylvania and Virginia, particularly in polls done by the respected Mason Dixon and Survey USA polls, but Obama still has an average of 7 points in Pennsylvania and 4 in Virginia, and he's still over the 50% mark. We regard the 50% mark as crucial because we expect most of the undecided to back McCain, although some just won't vote. We note that some other polling web sites and news organizations have colored Ohio and Florida blue, but we think both are still too hard to predict. Some have also moved Montana and Georgia into the toss-up category. There have been some gains by Obama in those states, but we still believe the evidence suggests they belong in McCain's camp. Advertisement Does our map mean we're predicting an Obama victory? Not exactly. We believe he holds a big advantage, and as we've said for a few weeks, McCain needs to catch a big break to turn it around and there's not much time left. It remains awfully hard to see how McCain can win. But this is a tough year to poll and to figure out the likely makeup of those who will actually cast ballots so no one should rule out surprises. As for the Senate races, we see Democrats with a lock on 54 seats and they're favored to add three others (Alaska, North Carolina and New Hampshire) for a likely total of at least 57. Odds are even in two others (Minnesota and Oregon), and Democrats have a reasonable chance for upset wins in Kentucky, Mississippi and Georgia. They could lose one seat after the election -- if Connecticut Joe Lieberman finally bolts. He may do that if Democrats punish him for supporting McCain. In the House, we see a gain of anywhere from 24 to 35, giving them as many as 270 of the 435 seats.