On the heels of a new federal budget plan unveiled Tuesday by Republican Rep. Paul Ryan, Democratic Congressional Campaign Committee Chairman Steve Israel is predicting the proposal "will be the defining issue in the midterm elections."

In remarks at the National Press Club on Wednesday, Israel panned Ryan's plan, which would cut federal spending by $5.1 trillion over 10 years in part by repealing Obamacare and trimming some federal entitlement programs -- and vowed Democrats would educate "voters early about what this budget means for them."

"When you have a budget that proactively hurts and weakens the middle class, people get angry," Israel said. "When they get angry, they vote."

Indeed, Ryan and his prior budget plans have proven to be valuable tools for Democrats in small-dollar fundraising appeals. Israel said the DCCC posted its best grassroots fundraising after Ryan spoke at the Republican National Convention in 2012 and when House Speaker John Boehner announced in February that Ryan would craft a new budget on behalf of House Republicans.

But even if Ryan's budget proposal helps House Democratic candidates at the polls in November, it remains unlikely Democrats will pose a serious threat to the House Republican majority this year.

Complicating Democratic efforts at energizing their voters and winning back seats is the nagging public-opinion drag of Obamacare, which has been met with disapproval by most Americans since going into effect last year. And even after President Obama this week celebrated 7 million people having enrolled in health insurance under the Affordable Care Act, Israel said it is "too early to say whether the tide has turned" on Obamacare as a political issue.

But, he added, "I think the climate will change on the Affordable Care Act."