An additional tool is needed to break U.S. government deadlocks. That tool could be enabling registered voters to vote in an issue-specific referendum that would be held whenever an issue cannot be resolved by the established government mechanisms of the House of Representatives, the Senate, and the Presidency.
Such referendums could be modeled after the Swiss approach, but perhaps with the proviso that referendums could only be placed on the ballot by a simple majority of either the House of Representatives or the Senate, or by the President.
No veto on holding a referendum would be allowed by any of these 3 over any other branch of government. And all 3 branches would be bound by the results of the referendum, which would be determined by a simple majority of all registered voters.