In the last few years, Republicans in Washington have tried to act--or if you're a cynic, appear to act--to stem the flow of illegal immigrants into the United States. Shortly before the 2006 midterm election, the Republican-led Congress approved 700 miles of double-layered border fence, only to see the current Congress largely gut the measure in 2007. Other legislation has funded enhanced border security. But as Congress has done a two-steps-forward-one-step-back border enforcement dance, the public seems to be becoming impatient for more.

Public opinion polls show that as the war in Iraq has faded somewhat as a priority for voters, a range of domestic issues are rising in importance--among them illegal immigration. In yesterday's voting in New Hampshire for example, exit polls showed that illegal immigration was a priority for the state's Republican primary voters (and illegal crossings aren't exactly a big problem in the state). Congressional Republicans have been saying for months that illegal immigration is invariably the top issue at townhall meetings--all across the country.

What can Republicans in Washington do to address these concerns?

Newsday columnist and Fox News contributor Jim Pinkerton has one possible answer: pledge to complete the double-layer border fence within six months of the convening of the next Congress. The pledge is explained and publicized at his fencebydatecertain blog. Early backers of the pledge include Congressman Walter Jones and former Arkansas Governor Mike Huckabee.

Pinkerton's effort--if successful--will force Republican candidates to take a firm stand on the border fence, and implicitly on tough enforcement in general. In a session yesterday at the Heritage Foundation, Pinkerton analogized it to the 'no new taxes' pledge pioneered by Grover Norquist of Americans for Tax Reform and, like Norquist, Pinkerton would make the pledge a litmus test for Republican candidates at the federal level. Given the strong feelings among core Republican voters, there might even be pressure to incorporate the fence pledge into the Republican candidate's platform--or in any agenda that Congressional Republicans may promise in 2008.

Read also Joe Mansour's post at TechRepublican.