Tea Party Republicans upset with House Majority Leader Eric Cantor's immigration push helped to torpedo his reelection Tuesday night, but Virginia political sources also give credit to Democrats who worked to undermine the No. 2 House leader by voting in the open primary.

Sources said the Democrats, some upset with the House GOP's stonewalling of President Obama's agenda and others mad the state Republicans took control of the state Senate this week, organized a get-out-the-vote effort to side with challenger Dave Brat, who beat Cantor.

“Some people who think the president is doing a reasonable job have argued back to me that Dave Brat will be even worse than Cantor. No. Dave Brat will be an inconsequential one-term backbencher howling against the oncoming tide,” said an email from a key Democratic anti-Cantor organizer Monday. “Leader Cantor losing because Obama supporters turned out to vote against him, will be the lead story in the national news on Wednesday,” it added.

Conservative sources Tuesday night, however, were taking the credit. “Cantor was expecting turnout of approximately 50,000. 65,000 voted. The extra 15,000 were not all Democrats. Conservatives were amped up. Maybe 3,000 to 5,000 Dems voted. Max. This success will have dozens of fathers,” said a key Virginia GOP source.

GOP establishment critic L. Brent Bozell III, chair of the group ForAmerica, said, "Eric Cantor's loss tonight is an apocalyptic moment for the GOP establishment. The grassroots is in revolt and marching. For the past five months ForAmerica has been advocating that the GOP leadership be replaced and today the voters in Eric Cantor's district removed him."

Another even suggested that the defeated Cantor should step down from his House leadership post.

What’s more, conservatives and Tea Party insiders said they hope to use the Cantor primary defeat to warn other Republicans who are too willing to compromise with Obama on key issues.

“I think this is just the first cycle of a multi-cycle effort. Democrats are moving left, and Republicans are moving right,” said a Tea Party leader.

For example, it is expected to energize supporters in Mississippi for Tea Party-backed candidate Chris McDaniel over long-serving Sen. Thad Cochran.

Paul Bedard, the Washington Examiner's "Washington Secrets" columnist, can be contacted at pbedard@washingtonexaminer.com.