Barack Obama has statistically significant leads over John McCain in four daily tracking polls today.

Gallup: Obama 50, McCain 42.

Diageo/Hotline: Obama 48, McCain 41.

Rasmussen Reports: Obama 51, McCain 45.

Research 2000: Obama 52, McCain 40.

We don't always post the daily tracking polls because they tend to be so incremental. However, Gallup today has Barack Obama opening a 50 percent to 42 percent lead in the surveying it did Sept. 25-27. The lead is just one point shy of his best showing this year, Gallup says. The survey period included the frenetic days when the Wall Street crisis reached a head, John McCain suspending his campaign and proposing postponement of the debates, plus one day of interviewing after the debates. A separate Gallup poll on just the debate itself declared Obama the winner by 12 points.

Rasmussen Report has Obama ahead 50 percent to 44 percent which Rasmussen also says is the biggest lead Obama has enjoyed in its daily tracking poll.

The Diageo/Hotline daily tracking poll had Obama ahead 47 percent to 42 percent.

Research 2000 puts Obama ahead 50 percent to 43 percent.

Gallup: Obama 49, McCain 44

Rasmussen Reports: Obama 48, McCain 48

Research 2000: Obama 49, McCain 42

Diageo/Hotline: Obama 45, McCain 44

Barack Obama and John McCain are tied at 48 percent each with 3 percent undecided in a new CNN/Opinion Research poll conducted Sept. 4-6.

A USA Today/Gallup poll we post earlier had McCain up 50 percent to 46 percent among registered voters and 54 percent to 44 percent among likely voters.

As far as the daily tracking polls:

• Diageo/Hotline: McCain and Obama tied at 44 percent each with 10 percent undecided in a survey conducted Sept 5.-7. That's a turnaround from Friday when Obama led 46 percent to 40 percent.
• Gallup: McCain leads 49 percent to 44 percent with 4 percent expressing no opinion, in a survey conducted Sept. 5-7. The margin of error is 2 points.
• Rasmussen Reports: McCain leads Obama by a statisitically insignificant 47 percent to 46 percent and has the same 1 point margin when "leaners" are included. Seventy-seven percent of Obama supporters say they are voting for him with enthusiasm compared to 65 percent for McCain, but McCain's figure is up from 54 percent before the GOP convention.

Now it's John McCain's turn. After Barack Obama got his post-convention bounce, opening up leads of 7 points or more, the Republican convention has helped McCain close the gap again. A CBS News poll conducted Sept. 1-3, before McCain's acceptance speech, has him tied with Obama at 42 percent with 12 percent undecided. The margin of error is 3 points. CBS's poll after the Democratic convention put Obama up by 8 points.

The opening days of the Republican fest made some dent in the "enthusiasm" gap with the number of McCain supporters saying they were enthusiastic rising from 25 percent to 35 percent. Fifty-five percent of Obama supporters described themselves as enthusiastic but that was down from 67 percent in the last poll.

Some other notes:

• Independents are divided.
• Sixty-nine percent of former supporters of Hillary Clinton say they are backing Obama, up from 58 percent.
• Sixty-six percent of white evangelicals are backing McCain, up from 57 percent.

Some more post-Democratic convention polls are coming out showing that Barack Obama got a bounce out of the party's meeting. Several show Obama with a statistically significant lead and one has the race tied.

A Diageo/Hotline poll conducted Aug. 29-31 has Obama ahead of John McCain 48 percent to 39 percent with 8 percent undecided. The margin of error is 3.5 percent. Before the convention, Obama had a 4 point lead. One reason is that Obama now leads McCain 42 percent to 33 percent among independents after trailing him 38 percent to 36 percent before the convention. Obama's favorable-to-unfavorable rating improved from 55 percent to 38 percent before the convention to 60 percent to 31 percent. McCain, at 51 percent to 41 percent, stayed about the same

Barack Obama leads John McCain 44 percent to 40 percent with 12 percent undecided in a Diageo/Hotline poll conducted during two periods, Aug. 18-20, and Aug. 18-24. The margin of error for parts of the poll not aimed at sounding out reaction to Obama's selection of Joe Biden is 3 percent. Fifty-five percent of Democrats were satisfied with the choice of Biden while 28 percent were not.

The poll identified strengths and weaknesses of Obama and McCain. Seventy percent of voters saw Obama as a great deal or somewhat in touch with the "average American" compared to 61 percent for McCain. Two-thirds also though Obama had done and excellent or good job of presenting himself as a potential president compared to 50 percent for McCain.

But as has helped McCain and plagued Obama in nearly every poll that tested some aspect of the experience factor voters said McCain was more prepared to lead the country as president by 58 percent to 34 percent.

On the economy, seen as the top issue by half of voters, Obama led McCain 48 percent to 40 percent.