Trump calls for Sanders to 'run as an Independent'

For what might be the first time in this campaign, Republican front-runner Donald Trump shared an opinion that supporters of Senator Bernie Sanders are likely to agree with on Tuesday when he said Sanders has been treated unfairly by Democrats and should run as an independent candidate.

"Bernie Sanders has been treated terribly by the Democrats—both with delegates & otherwise," he said in a tweet. "He should show them, and run as an Independent!"

While he hasn't gone so far as to threaten a third-party run, Sanders doesn't appear prepared to enthusiastically endorse Clinton if she wins the nomination. When asked at an MSNBC town hall on Monday if he would tell his supporters to back Clinton if he's not on the ballot come November, he stopped short.

"We're not a movement where I can snap my fingers and say to you or to anybody else what you should do, that you should all listen to me. You shouldn't. You make these decisions yourself," Sanders replied.

RELATED: Check out the latest power rankings to find out who's most likely to be the next president

Tuesday's tweet is far from the first time Trump has complained about the primary process and rules -- although the majority of his complaints up until now have been directed at the Republican Party.

Over the weekend Senator Ted Cruz and Ohio Governor John Kasich announced a joint "stop trump" partnership, saying they would stay out of each other's way in some upcoming state primaries. "Our goal is to have an open convention in Cleveland," Kasich's chief strategist John Weaver said in a statement. However latest reports indicate that the strategy may already be splintering.

SEE ALSO: Ku Klux Klan claims $20K in Clinton donations

%vine-url="https://vine.co/v/iU37UwQrE6h"%

Trump's comment toward Sanders came as voters were casting ballots in both the Democratic and Republican primary races in Connecticut, Maryland, Pennsylvania, Rhode Island and Delaware.

Clinton was considered the favorite in most states going into Tuesday, but polls show Sanders only a few points behind her in a handful of states -- meaning he could snag a victory or two on Tuesday.

But because of how the delegate math works, Clinton is still favored to make big gains. She is expected to walk away with 219 delegates, while Sanders is predicted to score 165, according to FiveThirtyEight.com. If all goes as predicted, Clinton's delegate lead would be almost 300.

SEE ALSO: Republicans Cruz, Kasich reach 'stop-Trump' deal

Sanders himself has not had many kind words for Trump in the past.

"We are not going to elect a President who insults people, every single day," Sanders said to supporters at a rally in March. "The American people will not elect Donald Trump president because he insults Mexicans; he insults Muslims; he insults women; he insults veterans; he insults the African American community."

RELATED: Check out the books the candidates have written