Sanders endorsed by Senate colleague; GOP head takes on Trump

Sen. Jeff Merkley of Oregon has become the first of Bernie Sanders’ Senate colleagues to endorse his presidential candidacy.

In an Op-Ed piece in The New York Times and in an appearance on MSNBC’s "Morning Joe" show Wednesday, Merkley gave Sanders high marks for resisting trade treaties that Sanders says has cost American jobs.

Merkley said in the broadcast interview that the Vermont senator has on many issues "been out there leading, clearly long before he decided to run."

In the Times piece, Merkley also cited Sanders’ positions on the dangers of global warming, and the "threats to our economy from high-risk strategies at our biggest banks." He said that Sanders has fought hard for military veterans, and he conceded he has an uphill battle ahead of him to win the Democratic nomination.

Meanwhile, the head of the Republican National Committee is lashing out at Donald Trump’s charges that the party’s presidential nomination process is "rigged."

RNC Chairman Reince Priebus responded to the GOP front-runner’s intensifying rhetoric on Twitter late Tuesday.

Priebus says the nomination process has been known for more than a year. He says, "It’s the responsibility of the campaigns to understand it. Complaints now? Give us all a break."

Trump is going on the attack as he struggles to keep pace with rival Ted Cruz’s delegate operation. Cruz made gains in Colorado, North Dakota, Louisiana and elsewhere by mastering the complicated state-by-state delegate selection process.

Trump told supporters in New York on Tuesday night that the "Republican system is absolutely rigged."

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