PALM BEACH, Fla. — In perhaps his most campaign-style speech so far, not-yet-official GOP presidential candidate Jeb Bush vowed Thursday not to alter his views on immigration despite intense opposition among some parts of the Republican base.

"If I go beyond the consideration of running, I'm not backing down from something that is a core belief," Bush told a gathering of the conservative Club for Growth in Florida. "Are we supposed to just cower because at the moment people are all upset about something? No way, no how."

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It was an issue Bush clearly wanted to talk about. As his 45-minute appearance neared its end, after about 25 minutes of speech and 20 minutes of question-and-answer, the moderator, Club for Growth President David McIntosh, was about to ask the last question when Bush interjected, "Can we do one about immigration?" Without a specific question to answer, Bush, a strong supporter of comprehensive immigration reform, began an extended discussion of his priorities on the issue.

Seen by a significant number of Republicans as weak on immigration, Bush stressed the toughness of his views. The current immigration system is broken, he said, "because we don't enforce the law. It's broken because we have a president that uses authority he doesn't have to pick and choose who gets to stay and who doesn't. It's broken because 40 percent of the illegal immigrants in our country came here legally and overstayed their time. It's broken because businesses sometimes hire illegal immigrants and they shouldn't do that and there should be true enforcement so that people know that that's the wrong thing."

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Bush went on to explain that he would rework the system to decrease family-based chain migration in favor of more economic immigration. And for those already here illegally, Bush outlined a position roughly consistent with other Republican immigration reformers. "My belief is we need to give people a path to legal status," Bush explained. "You pay your fines, you get provisional work permits, where you come out of the shadows, you pay taxes, you pay fines, you don't receive government assistance, you learn English, you don't commit crimes. Any of those things that you do would be a deportable offense."

Bush's presentation was more political in nature than other recent high-profile addresses, including his foreign policy speech in Chicago and appearance at the National Auto Dealers Association in San Francisco. In the first part of his remarks, Bush laid out his four top priorities for economic growth: 1) cut regulation, 2) simplify the tax code, 3) reform education, and 4) embrace the energy revolution. After that, Bush went through an extensive tour of his accomplishments during eight years as governor of Florida. Together, the two parts of his speech amounted to a far-reaching case for his presidential candidacy; Bush was working hard to sell himself to the crowd of influential conservative donors and activists.

Throughout, Bush managed to throw in the occasional bit of red meat in the midst of a positive-ideas agenda. For example, at one point, Bush said of President Obama, "This president has trampled over the Constitution on a regular basis" — a line sure to resonate with the most conservative Republicans. And yet in the next sentence, Bush added, "We can get upset about that, but that shouldn't stop us from also advancing positive ideas to help people move forward." All in all, it was a carefully balanced mix of conservative crowd pleasers and policy pitches on the eve of Bush's highly-anticipated appearance at the Conservative Political Action Conference in Washington.

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The former Florida governor was careful to include a few references to the fact that he is still officially considering whether to run for president, rather than actually running for president. But Bush's speech Thursday night was that of a man who seems ready to begin the next stage of his campaign.