Sen. Ted Cruz (R-TX) has just a four-point lead against Rep. Beto O’Rourke (D-TX), according to a new public poll from Marist College and NBC News.

Cruz leads O’Rourke by 49 percent to 45 percent in the poll of registered voters, a warning sign for the polarizing senator as he looks to win a second term. By contrast, Texas Gov. Greg Abbott (R) has a 19-point lead in the poll.

This survey is the latest to show Cruz with a lead in the low to mid-single digits in the Republican but Democratic-trending state — the last two public polls had him up by two and six points, respectively.

Cruz’s allies have been growing increasingly nervous about O’Rourke in recent months, given his telegenic campaign and the absolutely massive fundraising numbers he’s posted. And while Cruz remains the clear favorite, it looks more and more likely that O’Rourke will give him a tough fight this fall, giving Democrats one more potential tough route to the Senate majority in spite of the tough map they face.

Republicans have also been fretting about Cruz’s down-ticket impact. There are a number of GOP House members in tough races in the state in districts where other private polling shows him deeply underwater.

Marist is a reputable pollster, though some of their other surveys have looked much better for Democrats than other pollsters’ this election cycle.