MADISON, Wis. – His performance panned, President Barack Obama is changing his debate strategy against Republican Mitt Romney, aides conceding the president must find a crisper way to sell his agenda and counter his opponent without getting lost in the
weeds.

The heart of Obama’s new message with less than five weeks to go: Romney is a liar.

Expect that theme – expressed in softer terms from the president than from his aides – to drive Obama’s advertising and messaging for days. Wednesday night’s debate showed Obama was rusty, rambling and cautious, but his aides insist he emerged with a real opening to target Romney’s assertions.