Barack Obama hits 'crazy' Republicans as Trump falters

Ohio: Barack Obama sought to lash Republicans tight to their sinking White House nominee Donald Trump, as the outgoing US president visited the key swing state of Ohio Thursday.

With an eye on winning back control of Congress, Obama blamed Republicans writ large for backing a candidate who "proves himself unfit and unqualified" for the presidency "every time he talks."

Obama said that Trump came from a "swamp of crazy" that Republicans had cultivated over decades.

"They`ve been riding this tiger for a long time," he said. "They`ve been feeding their base all kinds of crazy for years."

Taking aim at the scandal over Trump`s bragging about groping women, Obama said that Republicans who have not disowned him should not be let off the hook.

"They don`t get credit for, at the very last minute when finally the guy that they nominated and they endorsed and they supported, is caught on tape saying things that no decent person would even think, much less say, much less brag about, much less laugh about or joke about, much less act on."

"The people who knew better didn`t say anything," Obama said. "They stood by while this happened."

"And Donald Trump -- as he is prone to do -- he didn`t build the building himself, he just slapped his name on it and took credit for it."

Hillary Clinton is now the favorite to win the White House, but the balance of the Senate and the House of Representatives is much less clear.

Republicans have controlled both houses of Congress for the entirety of Obama`s second term, thwarting many of his policy goals.

They are now fighting a rear-guard action to retain control, arguing implicitly that there needs to be a congressional check on a Clinton White House.

Obama`s remarks came in the usually pivotal battleground state, where Trump has long held a lead.

A poll on Thursday had Clinton marginally ahead.

But the state`s Democratic Senate nominee Ted Strickland -- who appeared on stage with Obama -- is getting pummeled.