SEATTLE -

The Washington state Senate is up for grabs, prompting money and attention to pour in for the handful of races that will decide which party will ultimately control the chamber.

Primary election voting wraps Tuesday, and while the contest won't settle whether Republicans or Democrats will have the majority, it offers a preview of key races heading into November.

The election cycle could ultimately break up a Republican-dominated alliance -- known as the Majority Coalition Caucus, led by former Democratic Sen. Rodney Tom -- that has run the state Senate for two legislative sessions.

The majority Republican coalition holds a 26-23 advantage in the Senate, meaning a swing of only a few seats could determine control. Twenty-five of the chamber's 49 seats are at play this year.