Washington (AFP) - Insisting that he won the US election and brawling with his own party's top senator, Donald Trump was back to demanding national attention this week. President Joe Biden just yawned.

"I'm tired of talking about Donald Trump, don't want to talk about him anymore," Biden said during a CNN town hall in Wisconsin on Tuesday night.

Trump is doing his best to get talked about.

Since grumpily departing the White House on January 20 and ceding to Biden, he has largely kept to himself.

But on Wednesday he marked the death of right-wing radio host Rush Limbaugh by calling into Fox News and reupping his false claim that he was robbed of victory in the November 3 election.

"Rush thought we won and so do I by the way. I think we won substantially," Trump said, adding how "angry" the country is about the supposed fraud, which no court has substantiated.

And on Tuesday Trump lit up the political landscape by firing a remarkable broadside at Senator Mitch McConnell, the senior Republican in Congress.

McConnell's sin was to have ripped Trump in a speech after helping to acquit the former president in last Saturday's impeachment trial.

McConnell did not join the seven rebel Republicans voting with Democrats to convict Trump for inciting insurrection at the Capitol on January 6. He stuck to the party line and in doing so likely ensured that the number of defectors remained just a trickle.

But having done his duty to Trump, McConnell then let loose, blaming him for a "disgraceful dereliction of duty" and recalling that the mob attacking the Capitol was "carrying his banners... screaming their loyalty to him."

Trump's riposte was a humdinger.

"Mitch is a dour, sullen, and unsmiling political hack," a statement from Trump's Florida retreat said.

That 'former guy'

How Biden was going to deal with the specter of a vengeful Trump has been a question ever since his convincing victory in November. Typically, former presidents fade gracefully into the background, but Trump is different.

Now Biden has given his answer.

"For four years all that's been in the news is Trump. In the next four years I want to make sure all the news is the American people," Biden said in the CNN town hall.

Throughout the appearance, Biden stuck to promoting a gigantic $1.9 trillion economic stimulus package and getting the country vaccinated against Covid-19. It's the same line he took during last week's impeachment trial drama and really ever since entering the Oval Office.

References he did make to Trump were notable mostly for their indifference.

The "former guy," he called him at one point.

So far, the tale of two presidents is working out better for the new one.

Polls consistently show broad support for Biden's Covid relief plans, as well as for his job performance.

Trump has dismal national approval ratings, even if he retains strong backing from hardcore Republicans.

And his threat to campaign against any Republican who refuses him wholehearted support throws a shadow over the party's fight for control of the legislature in the 2022 midterm elections.

"Mitch McConnell working with Donald Trump did a hell of a job. They are now at each other's throat. I'm more worried about 2022 than I've ever been," Senator Lindsey Graham, a Trump loyalist, told Fox News.

"I don't want to eat our own."