THE Senate coup in Olympia is a welcome development. The crossover of two moderate Democrats has created a legitimate Republican-Democrat coalition that demands a sustainable budget and protection of spending for education.

These are the two most important challenges in Washington. They are priorities that voters clearly support.

Instead of a liberal Democratic majority leader with Democrats at the head of all committees, the leader of the upper house will be a Democrat with six Republican committee chairs, six Democratic chairs and three co-chairs.

The power split is closer to being even than it has been in more than 100 years of state government.

Still, this is not a settlement negotiated between two caucuses, but between the minority Republicans and two Democrats. The Republicans will get the money committee, Ways and Means, which is to be given to the able Sen. Andy Hill of Redmond, one of the party’s rising stars.

The new majority leader will be Sen. Rodney Tom of Medina, a socially liberal Democrat and former Republican. Last spring he cooperated with Republicans to take over the floor to pass money-saving reforms that were being blocked by Democratic leadership.

Tom is a practical-minded legislator who prioritizes education and reflects the moderate character of the people of Washington.

The new caucus is a promising experiment. It is also a check on the power of the governor’s office and the House of Representatives, both of which remain firmly held by Democrats.

It’s encouraging that the Senate Democrats have acknowledged they are a minority.

In turn, the new caucus must deliver what it has promised: a sustainable budget and a commitment to funding education.