GOP districts have become whiter, more conservative

• The average Republican district is now 75%25 white
• GOP leaders have been pushing to rebrand the party with Hispanic voters
• Outside conservative groups are already mobilizing around immigration

Correction: A previous version of this story misstated the years comparing the demographics of white populations in Republican and Democratic congressional districts. The comparison is between 2010 and 2012.

WASHINGTON — Momentum to overhaul the nation's immigration laws is fueled by the growing political influence of Hispanics in America, but in the U.S. House there is diminishing incentive for Republicans to support the effort because their constituents have become whiter, more conservative and less diverse than the nation as a whole.

In 2012, the congressional district lines that make up the 435-seat chamber were redrawn as part of the once-a-decade process to balance out population shifts.

GOP-led redistricting efforts moved areas with high concentrations of predominantly Democratic minority voters out of GOP dominant districts and into Democratic-heavy districts, thereby making both districts less competitive in a general election.

According to the non-partisan Cook Political Report, House Republicans today represent 6.6 million fewer minorities than in 2010. The average GOP district is now 75% white, up 2 percentage points after the 2012 reconfiguration, while the average Democratic district is 51% white, down one percentage point since 2010.

"What's amazing is Republicans were able to actually make their districts ... whiter in the 2012 round of redistricting even though minorities were responsible for most of the growth of the U.S. population in the past 10 years," said David Wasserman, an election analyst for the Cook Report.

National Republican leaders, responding to a 2012 election where Mitt Romney garnered only 27% of the Hispanic vote, have been pushing to rebrand the party with Hispanic voters. The Republican National Committee outlined a new plan to woo the fast-growing electorate and on Tuesday named Jennifer Korn, former director of the conservative Hispanic Leadership Network, the committee's new director of Hispanic engagement.

But those national efforts don't necessarily matter to U.S House members whose districts have become less Hispanic. The 2010 redistricting resulted in a stronger GOP grip on the House, but also a political climate where incumbents are more vulnerable to primary challenges than general election battles, election analysts say, boosting the political pressure on incumbents to appeal to base voters. And voters in the Republican base are skeptical of proposals to make immigration easier.

Mindful of those political realities, Rep. Mario Diaz-Balart, R-Fla., a member of a bipartisan group of lawmakers attempting to craft a House immigration bill, said there is ongoing outreach to appeal to and assuage skeptical House conservatives.

Diaz-Balart said the group is crafting a bill that includes provisions popular among GOP constituencies, such as enhanced border security and restricted access to government services for unauthorized immigrants who get legal status.

He said he is also making a more emotional appeal to his colleagues' "sense of service."

"There are some folks that for them, this is a tough issue in a primary. Right. I get that," he said. "But the American people are demanding a fix to the broken immigration system. Knowing that, are you just going to sit back and do nothing because it might be a bit of a political risk? Then what are you doing here? What did you get elected for? This is why someone gets elected to Congress."

The Senate Judiciary Committee approved a bill last week that would allow the nation's 11 million unauthorized immigrants to apply for U.S. citizenship, add billions of dollars for border security and overhaul the legal immigration system to bring in more foreign workers.

Outside conservative groups are already mobilizing around immigration issues — in particular opposing giving a legal pathway to residency here for the undocumented immigrants residing in the U.S. — and the issue could become fodder for GOP primary challenges if the House moves forward with a bill.

Republican districts have less ideological diversity as well. Fifteen years ago, Cook rated 148 congressional seats safe for Republicans, while today there are 186 safe Republican seats, meaning 80% of Republicans face all but no threat of a general election challenge.

The districts Republicans control have also become more conservative, heightening pressure to appeal to more ideological constituents. Over the past two decades, the median Republican congressional district went from being seven points more Republican than the national average to 12 points more Republican than the national average. "If you're sitting in (a very conservative) seat, you really don't have any general election concerns whatsoever, the only thing you have to watch is a primary," Wasserman said.

Democratic districts have also become more liberal in the process, but Democrats hold a firm grip on fewer seats than Republicans and the party has not faced the same threat of primary challenges that the GOP has weathered in recent elections.

A May 1 national survey by the Pew Research Center on immigration legislation making its way through the Democratic-controlled Senate — which includes a pathway to citizenship — highlighted the partisan divide: Republicans knowledgeable about the bill oppose it nearly 2-to-1, 52%-27%, while Democrats knowledgeable about the bill support it nearly 3-to-1, 60%-18%.

Conservative Super PACs are already forming to target Republicans on immigration.

"It must be defeated in its entirety, period," said Lorie Medina, a Tea Party activist who chairs the Real Conservatives National Committee. The group has vowed to find and fund primary challengers to any Republican who supports a legislative overhaul similar to the Senate proposal, which the group considers an "amnesty" bill.

The group is organizing a series of events next month to test out voter canvassing technology and build grass-roots support, which they make a point to note is happening "a full eight months before the first Republican primary ballots will be cast in March 2014."

Inside the U.S. Capitol, GOP leaders are hesitant to lay down any clear directives on immigration. House Speaker John Boehner, R-Ohio, reiterated recently that the House "must act" on immigration. But when and with what remains unclear. "We'll let you know when we decide," Boehner said.