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Democrat Martin O’Malley’s campaign accused his rivals for the party's presidential nomination of ceding the immigration debate to Donald Trump because they are skipping an Iowa immigration forum this weekend.

O’Malley and former Sen. Lincoln Chafee, D-R.I., are the only two candidates planning to be at the #UniteIowa forum that is intended to be a bipartisan event promoting what its creator, Des Moines Register columnist Kyle Munson, intended to be a “thoughtful, statewide conversation on immigration.”

“Democrats should not cede the immigration debate to Donald Trump, but that’s exactly what they do when they skip critical forums like the first-ever #UniteIowa immigration forum,” O’Malley spokeswoman Gabriela Domenzain said Tuesday. “If anything it shows that Democrats are all words, no action when it comes to immigration.”

No Republican candidates, though invited, plan to attend the forum that begins Saturday afternoon at Buena Vista University in Storm Lake, Iowa. The university is in the district of Republican Rep. Steve King, known for his harsh position and comments about immigrants, such as saying that young immigrants have calves the size of cantaloupes because they haul drugs.

In a conference call with reporters, Munson said the coalition that organized the conference reached out to every campaign and went to staffers as well as groups such as College Republicans and other contacts to get as many candidates involved in the event as possible.

Munson said many campaigns, including Clinton’s, declined invitations to the event. On Tuesday Agriculture Commissioner Tom Vilsack, a former Iowa governor, endorsed Clinton.

The forum is intended to bring civility and depth to the discussion of immigration, Munson said. It will start with a bipartisan panel that includes immigration activists, a Republican economics professor, a businessman and local pastor.

Hillary Clinton was campaigning in Iowa Wednesday to disclose her plan for rural America.

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Symone Sanders, Sanders’ spokeswoman, said the campaign “would have loved to attend” but the event did not work with Sanders’ schedule. “Currently we have a table and organizers at the event,” she said.

Emily Benavides, spokeswoman for Jeb Bush, said no formal invitation to the event was received. "Governor Bush will not be in Iowa this weekend and will not be able to attend on such short notice. He regrets not being able to attend their event on Saturday and hopes to be involved in the future," Benavides said.

Many of the partners in the coalition that organized the event are pro-immigration and Munson acknowledged that could have kept away some Republican candidates. The College Republicans are organizers.

But the intention was to address an important issue for the state and lift the conversation on the issue. Campaign rhetoric on immigration has heated up and shifted right when Republican Donald Trump declared his presidential bid by saying Mexico was sending criminals, rapists and drug couriers across the border.

“This is designed as a unique forum on what we knew would be a key issue and what has become a much hotter issue this summer,” Munson said.

Iowa holds party caucuses in February. Joe Enriquez Henry, national vice president-Midwest for the League of United Latin American Citizens, (LULAC), said his group and others are working to increase Latino turnout at the caucuses, which has been around 1,500 voters generally.

“This time it’s going to change. We have a lot of young Latinos who have reached adult age and are registered to vote. We have registered at least 50,000 Latino voters – that’s higher than ever before,” Henry said. “The key thing is (for Latinos) to not only vote in 2016, but to participate in caucuses in 2016.”

He said LULAC is working to increase Latino caucus turnout to 10 to 20 percent of overall turnout.

Immigrants are rebuilding rural communities in Iowa and their contribution needs to be discussed more, Henry said.

"With that, we have a strong voice," Henry said. "Many Democratic candidates are taking it for granted Latinos will be there and that's not necessarily the case."

Brad Best, a political scientist with Buena Vista University in Storm Lake, Iowa, conjectured that “party elites" may not find it convenient for their campaigns to drill down more deeply on the issue as opposed to sticking with “the language of partisanship” on the trail.

Domenzain said O’Malley chose to attend because he is “unafraid to talk about his record on this issue and progressive plan to fix our inhumane immigration system.”

“Leadership is about forging a new consensus and that is what Gov. O’Malley is doing by talking about immigration in every community – not just in front of a Latino audience,” said Domenzain.

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