WASHINGTON – In nominating Thomas Perez for secretary of labor, President Obama is making his most polarizing, his most confrontational Cabinet choice ever. And there's little Republicans can do about it except grouse.

A zealous liberal star raised in Amherst, who worked his way through Canisius High School, Brown University and Harvard, Perez symbolizes every reason the GOP lost the election rolled into one man.

Obama's wedge campaign themes, like the Republicans' alleged war on women and purported attempts to discourage blacks and Hispanics from voting, found echoes in the vigorous prosecutions brought by Perez, as assistant attorney general for civil rights.

So far, the only obstacle the GOP minority has put in Perez's path has been the “hold” placed against his Senate confirmation by Sen. David Vitter, R-La., who turned up six years ago as a john in a prostitution scandal involving the “D.C. Madam.” While the Senate has received Perez's nomination, a date for his confirmation hearing is pending.

Republicans from safe states will ask Perez about an act that signaled the Obama administration's attitude toward black political activism – the suppression of a federal case against the New Black Panthers. Career Justice Department lawyers charged the Panthers, considered by some to be a hate group, with intimidating Philadelphia voters in the 2008 campaign. Under Obama's new attorney general, Eric Holder, and Perez, the case was summarily dropped.

Conservatives have charged that Perez prevaricated in testimony in a U.S. Civil Rights Commission probe of the episode. But a White House official told this column, “Perez's statement to the commission was accurate…and Perez had not intentionally misled [the investigators].” A Justice Department Inspector General's report did cite “a troubling history of polarization in the Voting Rights” section, which Perez supervised.

A semaphore was sent to Hispanic voters in 2010 when Perez opposed Arizona's tough law permitting police to question people randomly about their immigration status. Arizona passed the law because Republicans believed Obama told federal officers to relax sanctions against illegals, who were almost all Hispanics.

Perez said, “You can't have 50 states making immigration law and have a coherent system.” Obama last July followed that up by suspending the deportation of thousands of immigration law violators. Obama won 71 percent of the Latino vote four months later.

The White House did not respond to questions about Perez and the Mary Susan Pine case. Justice charged Pine, a Florida pro-life activist, with violating the Freedom of Access to Clinic Entrances. FACE is designed to prevent militants from blocking the entrances to abortion clinics. Perez bragged his section opened 20 civil probes and filed eight complaints under the FACE Act compared to just one over the previous eight years.

Justice charged Pine stepped in front of a car and passed a pro-life pamphlet through an open window. The federal judge in West Palm Beach last year threw out the case, wondered aloud why the government prosecuted her and ordered her paid $120,000 for her defense costs. The judge questioned whether the prosecution “was the product of a concerted effort between the government and the [abortion provider] which began well before the incident at issue, to quell Ms. Pine's activities.”

The Congressional Hispanic Caucus, the labor movement, and La Raza, the nation's leading Latino advocacy group, have enthusiastically backed Perez's confirmation. With Republicans squirming to win back some of the Hispanic vote, look for the GOP to mount a structured, even muted opposition.

The Perez choice will help with conservative fund-raising and offer themes for talk radio. Would that the country had such an enthusiast probing investment houses and the oil companies.