WASHINGTON — Former Bush administration Homeland Security Secretary Tom Ridge has a simple message for opponents of comprehensive immigration reform within the Republican Party — you're "flat, dead wrong."

"I think there's an art to governing and part of the art of governing is recognizing the reality as it exists, not as you want it to be. Part of the reality is that some people on my side of the aisle do not understand is that even if you can identify those 10 or 12 million illegals here, you're not going to round them up, put them on 747s, and send them home," Ridge said in an interview with BuzzFeed.

"Number two, by and large, 99.9 percent of them, I think, have been basically — they are trying to be responsible, thoughtful, law-abiding people and a very, very few small minority are breaking the law. And, by the way, they're also contributing in many different ways to the success and the diversity of the economy," Ridge said of undocumented workers in the United States.

As DHS Secretary, he said, "I was down in a lot of those detention centers along the southern border, in Arizona and New Mexico. I don't find those people coming across the border trying to harm us. They're trying to take advantage of what we've always stood for, and that's opportunity, economic and political freedom," the former Pennsylvania Governor said.

Ridge is no stranger to the internal fights over immigration within the GOP. During his time in the Bush administration, for instance, he found himself at odds with the White House, which was widely viewed as too progressive on the issue for most conservatives, at one point.

"I thought about it a long time, not just as the secretary overseeing the immigration and citizenship service, I thought about it a long time as a social issue, an economic issue, a political issue," Ridge said, explaining that he inadvertently outlined at a town hall meeting what amounted to what he called the "Ridge plan" for reform.

In 2003, The New York Times reported that Ridge "called for millions of illegal immigrants in the United States to be given some sort of legal status short of citizenship" at the town hall meeting.

"A couple hours later," Ridge said, "we got a call from the White House saying, 'What the hell you doing laying out an immigration plan when the president hasn't laid out his yet?'"

As to why he supports reform, Ridge bluntly said, "At the end of the day, I think we're just flat, dead wrong on the issue. We're not sending them back, I don't know why we can't reach a compromise. And, by the way, 'compromise' is not a dirty word in my lexicon, it's part of the art of governing."

Ridge, like many former Bush administration officials, has become increasingly vocal in his criticism of the Republican Party's ideological drift. During a Log Cabin Republicans dinner Wednesday, Ridge argued against the Tea Party ideology, asking, "Are we a fractured party of purists and ideologues, or are we going to become a united party of ideas?"

Although he focused on marriage equality and the party's treatment of gay issues on Wednesday, Ridge is making a larger argument — advanced by some of the party elite in DC throughout this year — that the party needs to moderate on social issues more broadly if it wants to be able to bring in more, and younger, voters.

But make no mistake, Ridge isn't becoming an Obama backer, and had hard words for the administrations handling of his old agency.

For instance, on the administration expansion of domestic surveillance, which started during his time at DHS, Ridge said initially "they would use a, basically an electronic vacuum cleaner and pull down email connections, i.e., you emailed me and I emailed you, we don't know the content. Technically, we were told that the content wasn't pulled out, but we're learning more and more that some of the content has been retained and reviewed. That gets to become very, very troubling."

"It's that classic debate: Are we willing to surrender the privacy to have absolute security? And I say, 'No, hell no.' I think we all oughtta be troubled. I frankly don't know if these young people appreciate, truly appreciate how much information about themselves is floating out there in that digital universe," he said.

"We gotta make sure that certain private matters that we may be willing to exchange for convenience … don't necessarily end up in a government databank. We better be worried about that forevermore."

As for his old job, the tenure of Secretary Janet Napolitano and the nomination of former Department of Defense General Counsel Jeh Johnson to take the helm at DHS, Ridge expressed support for Johnson and says he was "sensitive" to criticism faced by Napolitano. He criticized, however, Obama's relationship with and support of the department.

"I don't think the president has given the department the kind of public and potentially private support that it needs from the White House," Ridge said. "I met with Mr. Johnson the other day, and the fact that he is a friend, and a trusted friend, of the president may mean that some of the deficiencies that still exist — and that's the Coast Guard still not getting the support that it deserves and a few other challenges that they have — might be remedied in the near future."

Rather than criticizing DHS itself, though, Ridge said, "I am more concerned by the fact that I still understand that they still don't get the kind of information on a regular basis that they need. There are a couple of times that I was very sensitive to the criticism that [former DHS] Secretary [Janet] Napolitano received because the department was criticized for not acting but, frankly, they were unable to act because other agencies had information and didn't share it with them and that was a challenge as far as I'm concerned."

Ridge also blamed some of DHS' woes on its understaffing. "The other challenge, I think they have, and here's where President Obama and his team have really gotten off the dime … is they got too many vacancies. I mean, how can you have an agency of that size, and that complex, and that many missions, and I think they have 14 vacancies or acting positions," he said, a problem discussed with Foreign Policy earlier this year, which appears to continue to be an issue.

"I find that totally unacceptable," Ridge said. "I hope that he'll support his friend, Secretary Johnson, by getting his staff to get off their backside and get some quality people up to support Secretary Johnson. It's outrageous! It's outrageous that they have this many vacancies. And then they call in this man to try and run the agency when he's got major management challenges, and nobody filling slots."