WASHINGTON — In tiny Rhode Island, it seems hell hath no fury like a Democrat scorned.

A day after learning he was being snubbed by the President of the United States, Democratic gubernatorial candidate Frank Caprio let voters in the Ocean State know exactly what he thought of Barack Obama.

"He can take his endorsement and really shove it as far as I am concerned," Caprio said Monday.

The angry presidential tell-off was sparked by one of the most unusual political decisions Obama has made during the 2010 midterm election season.

Even as he criss-crosses the country pleading with Democrats to support their local candidates at the ballot box, Obama himself chose personal loyalty over party loyalty in the hotly contested governor's race in Rhode Island.

Obama declined to offer his support for Caprio, the state's general treasurer, for fear the endorsement would hurt the Democrat's opponent — former Republican senator Lincoln Chafee, 57, who is running for governor as an Independent.

"Out of respect for his friend Lincoln Chafee, the president decided to stay out of the race," White House spokesman Bill Burton said. "The president feels comfortable with what he's doing in this race."

Responding to Caprio's remarks about Obama, Burton said only that "emotions are running high" as the Nov. 2 election approaches.

With polls showing the vote could be a disastrous one for Democrats, a president's endorsement can help make-or-break a close race. In the past week alone, Obama has made personal visits to help vulnerable Democrats in Nevada, Oregon, California, Washington.

Obama has not just limited his campaigning to congressional races, where Democratic losses could have a direct impact on his ability to govern, but has stumped for several of the party's gubernatorial candidates, including Jerry Brown in California and Kendrick Meek in Florida.

And the president visited Minnesota on the weekend to support the gubernatorial candidacy of Mark Dayton, a former Democratic senator who holds a narrow poll lead over his Republican challenger.

By most accounts, Caprio, 44, could have used Obama's support in Rhode Island. A Rasmussen Reports poll, conducted Oct. 21, showed the Democrat trailing Chafee by seven percentage points.

While Obama has had a personal friendship with Chafee — the two men served together in the Senate for two years — there has been speculation Caprio's reputation as a conservative Democrat may have factored into his decision to stay neutral in the race.

The controversy erupted just as Obama paid a visit to Rhode Island on Monday to hold fundraising rallies for other Democratic candidates.

Caprio had planned to attend Obama's events, but cancelled after learning from a reporter that no presidential endorsement would be forthcoming.

He accused the White House of treating Rhode Island like "an ATM machine" to bolster Democratic coffers while tacitly backing the party's opponent.

"I never asked President Obama for his endorsement and what's going on here is really Washington insider politics at its worst," Caprio told a Rhode Island radio station.

"What I'm saying to President Obama very clearly is, I'll wear as a badge of honour and a badge of courage that he doesn't want to endorse me as a Democrat, because I am a different kind of Democrat."

Though he is a lifelong Democrat, Caprio irked some in the party by meeting with Republican National Committee chairman Michael Steele earlier this year — briefly prompting speculation he might run for the GOP.

But Steele, who was also in Rhode Island on Monday, said he never discussed with Caprio the possibility of switching parties. Obama's refusal to endorse his own party's candidate was "insulting, when you think about it," Steele said.

Nathan Daschle, director of the Democratic Governors Association, told Politico that Obama's decision was "disappointing" because Caprio had spent his career fighting for the party's values.