Don't get your hopes up yet. I think the researchers are exaggerating the areas of agreement and overlooking strong evidence of disagreement on things that matter. The actual tables are here.
What jumps out at me are the following:
- On almost every issues, the congressional Republicans are significantly more critical of international institutions and international security agreements than their executive branch counterparts. It also turns out that they are about a decade younger -- suggesting they are the next generation of GOP leaders on these issues.
- Republicans in general seem basically opposed to international efforts to limit the spread of nuclear weapons, compared to Democrats. Congressional Republicans don't even support George W. Bush's Proliferation Security Initiative.
- The only one of the four groups still favorable to U.S. relations with Irag and Afghanistan is executive branch Republicans.
- There is a profound split on climate change, with only 10% of executive branch and 3% [!] of congressional Republicans considering it an important issue.