WASHINGTON — Rep. Michael Grimm is in the middle of a tug of war for his vote on immigration reform.

Redistricting has pushed his Staten Island district to the left and helped make Grimm the No. 1 target in New York City congressional elections, dramatically raising the stakes for his immigration vote.

The two-term Republican is caught between his Tea Party base, which wants him to dig in on border security, and the Catholic Church and Hispanic voters, pulling him to support a path to citizenship for illegal aliens.

Grimm has softened his once-staunch opposition to “amnesty” for America’s 11 million undocumented residents, saying that he currently opposes “blanket amnesty.”

Still, he has vowed to close borders, overhaul visa programs and institute a national E-Verify system to check the immigration status of job seekers.

“He has moved on this issue,” fumed Staten Island Tea Party leader Frank Santarpia.