Former Secretary of State Hillary Clinton has a solid lead in Iowa, according to a Public Policy Polling survey released Friday, with Sen. Bernie Sanders (I-VT) trailing by 8 points.

The PPP poll showed support for Clinton at 48 percent among Iowans likely to attend the Democratic caucuses, while Sanders stood at 40 percent. These results indicate a slightly wider lead for Clinton than when the same poll was conducted earlier this month, showing Clinton at 46 percent to Sanders’ 40 percent.

The Iowa race is crucial in the battle for the Democratic nomination, as polling in New Hampshire suggests a consolidating advantage for Sanders while Clinton has a clear lead in virtually all South Carolina polls. Different pollsters have shown a wide range of results for Iowa Democrats.

Former Maryland Gov. Martin O’Malley showed 7 percent support in the PPP poll, near the upper limit of his support in any state or national survey (although down from 8 percent in PPP’s early-January poll). That showing could be important in the Iowa caucuses, as supporters of candidates who fail to meet a 15 percent threshold are required to redistribute their support to other candidates. O’Malley supporters, when asked about their second choice, preferred Sanders to Clinton by a 30-point margin, 57 percent to 27 percent.

The PPP poll was carried out form Jan. 26-27. Pollsters surveyed 851 likely Democratic caucusgoers, with a margin of error of 3.4 percentage points.