Montana state Senate President Jon Tester beat state Auditor John Morrison in the state’s Democratic Senate primary by wide margins yesterday. He goes on to challenge Republican Senator Conrad Burns, who beat state Senate Minority Leader Bob Keenan.

Tester managed to win by a 26 point margin, despite being outspent by Morrison two-to-one and lacking support from the Democratic establishment. He instead relied on a grassroots campaign and internet-based organizing. On the Republican side, Keenan lost to the three-term Senator Burns by over 47,000 votes, or 22 to 72 percent, indicating that instead of casting protest votes Republicans instead chose to stay at home.

According to the latest results, with 98 percent of precincts reporting, far more Democrats showed up at the polls Tuesday then Republicans. 105,952 Democrats voted in the Senate primary, compared to 94,611 Republicans. (Of course, in the general turn out will be higher). In perhaps a sign of his changing political fortune, Burns received 102,125 votes in the 2000 primary when he had no challenger, compared to only 68,511 this time around.

Will voter dissatisfaction with Burns’ ethics problems allow Tester to pick up independent and Republican votes? That will be the question of the election.