The gap between Sen. Bernie Sanders (I-VT) and Hillary Clinton in New Hampshire has narrowed over the course of the week, though Sanders still holds a comfortable lead in the key early state, according to the University of Massachusetts Lowell tracking poll released on Friday morning.

In the Friday poll, Sanders earned 55 percent support and Clinton earned 40 percent support among likely Democratic voters in the state. Since the UMass tracking poll released on Thursday, Clinton jumped 4 percentage points while Sanders dropped 3 percentage points.

Since the first tracking poll released on Monday, Clinton has gained 10 percentage points, when she polled at 30 percent in the UMass tracking poll. Sanders saw his biggest lead on Tuesday with 63 percent support, and he has dropped 8 percentage points since then in the tracking poll.

TPM’s Polltracker average shows Sanders leading Clinton in New Hampshire 57.1 to 35.7.

The UMass poll, sponsored by Boston news station WHDH, was conducted from Feb. 2-4 via phone. They surveyed 434 likely Democratic voters with a margin of error plus or minus 5.24 percentage points.

Correction: This post incorrectly stated that the margin of error among likely Democratic voters was plus or minus 2.89 percentage points. The margin of error is 5.24 percentage points.