GOP convention planners are trying to deal with the fact that few governors, Senators, and senatorial candidates will be attending the gathering in July. 

Along with dozens of House members likely to skip the conclave, the absence of establishment Republicans may undercut Trump's call for party unity, say some analysts.

But other say that Trump doesn't need these politicians anyway - he won without them and will go on without their support if necessary.

Fox News:

A growing roster of senior GOP figures – from governors to senators to, most notably, nearly every living GOP presidential nominee – is vowing to skip the convention in Cleveland, despite the candidate starting to win over the rank-and-file.

In an unconventional election season where Trump has capitalized on an anti-establishment fervor, the case can be made that Trump does not need the blessing of party elders, or their attendance.

“Trump is a master entertainer and more than likely going to put together a convention program that attempts to highlight his strengths and sideline some of the major absences,” Republican strategist Ron Bonjean told FoxNews.com.

Still, since wrapping up the nomination, Trump and his surrogates have been regularly meeting with Hill Republicans, showing at least an effort to pursue party unity – a message that high-profile absences in Cleveland could undercut.

Trump hit the unity theme again Sunday night, as he responded to the latest prediction that an independent candidate would soon enter the race. On Twitter, Trump warned, “if the GOP can't control their own, then they are not a party.”

Yet Trump’s contemporaries will be nowhere near Cleveland.

Of all the living Republican presidential nominees and former presidents, only Bob Dole is expected to attend – and even then, only “briefly,” for the purpose of catching a luncheon hosted by his law firm, a source told Fox News earlier this month.

Former Presidents George H.W. Bush and George W. Bush have said they will not attend, as have 2008 nominee John McCain and 2012 nominee Mitt Romney. Former 2016 White House candidate Jeb Bush also is expected to skip.

Of them, Romney is working most actively against Trump, having delivered a major address attacking his candidacy and frequently sparring with the now-presumptive nominee on Twitter. He also reportedly has been the focus of efforts to recruit an independent candidate, though so far to no avail.

Others claim to be skipping in order to focus on their own election battles – some of those potentially made more challenging by Trump’s primary success.

McCain seemingly counts himself among that group. The Arizona senator is facing a tough re-election fight in a state with a heavy Hispanic population, and has said Trump complicates his race.

New Hampshire Sen. Kelly Ayotte also has said she will not be attending the convention, citing a tough re-election battle.

"Unlikely," Ayotte told CNN. "I've got a lot of work to do in New Hampshire, I have my own re-election and I'm going to be focusing on my voters in New Hampshire."

Other lawmakers in tight election battles who do not plan to be in Cleveland include: North Carolina’s Richard Burr, Wisconsin’s Ron Johnson, Alaska’s Lisa Murkowski, Kansas’ Jerry Moran, Missouri’s Roy Blunt, and Illinois’ Mark Kirk, according to McClatchyDC.

It should be noted that in previous presidential years, some House and Senate candidates locked in tight reelection battles have passed up the party convention. But the absence of so many key GOP players suggests that this year, the no-shows will be unprecedented.

Given the fervor of anti-establishment Republcians, Trump certainly won't lose any support because he can't get many party leaders to back him. But he has the RNC behind him, who will apparently play a big role in running his national campaign. The national party will also assist the candidate in fundraising and get out the vote efforts.

Trump may not unite the entire party. But he is likely to go into the November election with strong support from the party base and most conservatives behind him as well. Ironically, the race may turn on how many Democrats Trump can pull from Hillary Clinton - a prospect that worries the Democrat's campaign and will no doubt complicate her messaging in the fall.