How the left plans to replace America:
1. Open the borders to a tidal wave of Third World immigrants who do not share American values, traditions, cultures or beliefs. Most of these folks are less educated and do not understand nor care about politics, economics, or constitutional government. These immigrants vote overwhelmingly for the Democrat Party. They will vote for anyone promising free stuff, and willingly trade long term prosperity and stability for short term advantages. In short, they are more manageable and trainable to support leftist goals. They also have more children, thus growing their numbers over time.
Millions of non-voting illegal immigrants are now among us, and may provide the tipping point for making the leftist Democrats a permanent majority party. Recent calls, even by so-called Republicans, to grant these immigrants amnesty and make citizens of them, will achieve this.
2. Marginalize white people and reduce their numbers. Recent voting patterns prove that white people, especially white men, are the ethnicity most resistant to the goals of the Neo-Marxists, i.e. replacement of capitalism with socialism, massive wealth redistribution, and social regimentation. Not surprisingly, white men are the single most hated group by left wingers, and this is why whites are being targeted on college campuses. Whites must be replaced, and marginalized while they are being replaced, with feelings of shame and guilt over imaginary wrongs. Not surprisingly, whites are not replacing themselves through birthrates, and the white demographic is self-destructing. It is only a matter of time before whites are effectively replaced, taking their culture, nation and traditions with them.
The above two factors constitute population replacement. Before the left can replace America with something else, they must replace those who made it, believe in it, and maintain it.
What we on the right are missing are (1) a correct definition and description of the problem, and (2) effective strategies for reversing the above two trends.