In a Zogby poll taken for the Houston Chronicle to coincide with the start of early voting, the results showed Barack Obama with a 7-point lead over John McCain in Harris County and Rick Noriega with a similar lead over John Cornyn. The poll was published by the Houston Chronicle on Saturday. The sample was 602 likely voters and had a margin of error of 4.1%. Fewer than 40% of the respondents identified themselves as black or Hispanic, and the poll gave these responses extra weight to bring the numbers in line with Harris County demographics. Houston blogger Charles Kuffner has his doubts about the survey: The first thing everyone is going to latch on to is the partisan breakdown of the sample, which is 46D/37.5R/16.5I. I have to say, that seems a little Democrat-heavy to me. I have no trouble believing that the Dems have erased the Republican’s lead here, and can believe they have nosed ahead, but an 8.5 point gap in the Dems’ favor strikes me as excessive. Needless to say, I’ll be delighted to be wrong about that. The Chronicle also plans to publish poll results for Harris County offices and judges on Sunday and for the John Culberson – Michael Skelly congressional race (CD #7) and the Nick Lampson – Pete Olson race (CD# 22) on Monday.