President Barack Obama derided his Republican adversaries on a visit to the US heartland Monday, saying their slogan for the upcoming mid-term elections was "No, we can't."

"You remember when I was running? We had a little slogan, 'Yes, we can.' These guys' slogan is 'No, we can't,'" he said at a fund-raising event for the Democratic candidate for governor of Wisconsin.

The president is hitting five states in three days, criss-crossing the country from Wisconsin to California to Florida to Washington State to Ohio to drum up support for Democrats facing tough elections in November.

Obama charged that his Republican opponents have systematically opposed his reforms in Congress.

Ticking off examples, he said: "No on closing loopholes for companies that ship jobs overseas. No on the tax cuts for small businesses. No on the clean energy jobs, no on railroad and highway projects.

"Just this weekend, the Republican leader in the Senate said, this is a quote: 'I wish we had been able to obstruct more.' Obstruct more! Is that even possible?"

While Republicans might think that will serve them well in the next elections, Obama said his priority was "to think about the future. And that's the difference. That's the choice in this election."

Up for grabs is a third of the US Senate and the entire House of Representatives. Voters also will elect governors of 37 of the 50 US states in November.

Democrats currently hold majorities in both houses of Congress, but do not have enough of a margin in the Senate to block Republican filibusters.