SEATTLE — Democrats are likely to retain their numerical majority in the state Senate, but three undecided races will determine their margin over Republicans.

So far, Democrats are likely to lose a seat in the 10th district, where incumbent Sen. Mary Margaret Haugen is trailing Rep. Barbara Bailey by 5 points. The district covers Island County and sections of Snohomish and Skagit counties.

But Republicans are also likely to lose a seat in eastern King County. Democrat candidate Mark Mullet is leading Republican Brad Toft in the 5th district race by 8 points. The seat was formerly held by a Republican.

The closest race is in the Vancouver area, where after Wednesday’s vote update Democratic Rep. Tim Probst led incumbent Republican Sen. Don Benton by just 102 votes.

Currently, Democrats have a 27-22 majority.