Donald Trump's campaign chief says "The Bush Family… Are the Past. We’re Dealing with the Future"

Trump campaign chief says convention-boycotting Bushes are 'part of the past' and Trump is 'the future' as he blasts Ohio Gov. John Kasich for 'embarrassing his state' by not showing up.l

Republicans refusing to come to this week's GOP convention in Cleveland are receiving a dose of shame from allies of presumptive nominee Donald Trump.

Trump campaign chairman Paul Manafort said Monday that the Bush family, who aren't setting foot in Cleveland this week, are 'part of the past,' while Trump is 'the future' of the Republican Party.

He tsk-tsked Ohio Gov. John Kasich for refusing to enter the convention hall even though the convention is taking place in his home state.

And former House Speaker Newt Gingrich, overlooked for Trump's running-mate slot, said the entire Bush family is behaving 'childishly' by not showing up.

Manafort appeared on Morning Joe to push back against co-host Mika Brzezinski's contention that a weak lineup suggested 'that they couldn't get anybody to speak.'

He reinforced the many senators who aren't coming, along with the party's past nominees and former presidents, are has-beens.

'Most of the Republicans who aren't coming are people who have been part of the past,' Manafort said. 'And the people who are part of the future of the Republican Party are, frankly, going to be here participating in the program.'

Former presidents George H.W. and George W. Bush, specifically, are GOP dinosaurs, he added in the GOP's morning press briefing.

'The Bush family, while we would like to have had them, they have not been – you know, they're part of the past. I mean, we're dealing with the future,' he said.

'We're fixing, really, the issues that relate to the future. And so while we'd like to have them, they do not reflect the broad strokes of the Republican Party.'

On 'Morning Joe,' Manafort took special aim at Kasich – the Buckeye State governor who also vied for the presidential nomination but is staying away this week.

'He's making a big mistake. He's making a big mistake. He's looking at something that's not going to happen,' Manafort began.

'He's hurting his state. He's embarrassing his state, frankly,' the campaign chairman said.

Gingrich, talking to George Stephanopoulos on 'Good Morning America,' aimed his ire at the Bush family, with Trump's former rival Jeb Bush and former presidents George W. Bush and George H.W. Bush all missing out.

Jeb Bush even told MSNBC last week that he was so disappointed by the party's pick in Trump, and couldn't bring himself to support Democrat Hillary Clinton, that he wouldn't be voting for either candidate in November.

'The Bushes, I think, are behaving childishly,' Gingrich said Monday. 'Jeb lost. Get over it.'

'The fact is this Republican Party has been awfully good to the Bushes.'

Manafort told reporters during the mid-morning briefing that 'many of the delegates who supported Jeb Bush, many of the delegates – most of the delegates – who supported the other candidates are now supporting Donald Trump at this convention.'

'There's a few that still aren't, but by and large ... there are no more than are traditionally part of the convention. Conventions are a healing time. They're not a time when everything is finally done. We feel, however, the healing time is happening. And when we leave here, by and large it's going to be a united Republican Party.'

Manafort also argued on MSNBC that because Trump is a political 'outsider,' a roster of politicians at the speakers' podium doesn't really make sense.

'What we're trying to accomplish is not to have a heavily laden program of politicians, but the goal of this convention for Donald Trump is to show the rest of the story of who Donald Trump is,' Manafort said.

'And so to tell that story, you don't want politicians who don't know him; frankly he's the outsider.'