A SurveyUSA poll conducted Feb.17-18 shows Hillary Clinton ahead of Barack Obama in one of her “firewall” states by 52 percent to 43 percent, with a 3.7 percent margin of error. While comparing the results of different pollsters to each other can be risky business, this outcome compares with two polls conducted last week that had Clinton ahead with healthy double-digit margins. Clinton already has received some unsettling news from recent polls in Texas that showed her lead there eroding.