GOP front-runner Donald TrumpDonald John TrumpDems flip Wisconsin state Senate seat Sessions: 'We should be like Canada' in how we take in immigrants GOP rep: 'Sheet metal and garbage' everywhere in Haiti MORE has bumped Ted CruzRafael (Ted) Edward CruzWith religious liberty memo, Trump made America free to be faithful again Interstate compacts aren't the right way to fix occupational licensing laws Texas Dem: ‘I don’t know what to believe’ about what Trump wants for wall MORE from the lead in Iowa just a month before the first-in-the-nation caucuses, according to a new online poll.

Trump, with 39 percent, has a 5-point lead among likely Republican caucus-goers over Cruz, a CBS News “Battleground Tracker” poll released Sunday morning shows. Marco RubioMarco Antonio RubioOvernight Cybersecurity: Bipartisan bill aims to deter election interference | Russian hackers target Senate | House Intel panel subpoenas Bannon | DHS giving 'active defense' cyber tools to private sector Senators unveil bipartisan push to deter future election interference Puerto Rico's children need recovery funds MORE is in third place, with 13 percent.

Pollsters found that Trump cut into Cruz’s support among Tea Partiers and evangelicals in Iowa, CBS said.

The New Hampshire race is unchanged, according to the new poll, with Trump holding a wide lead over Cruz and Rubio. John Kasich is now in fourth place, however, replacing Gov. Chris Christie.

Trump also still holds a double-digit lead in South Carolina, CBS found.

The online polling firm YouGov conducted the poll for CBS. It has a 7.2 percent margin of error in Iowa, 6.8 percent margin of error in New Hampshire and 5.7 percent margin of error in South Carolina.