The Sanford Underground Lab’s main aim: to discover the nature of the mysterious “dark matter” that accounts for almost 90 percent of mass

If you don’t include the 70 % that’s dark energy, anyway (otherwise it drops to about 25 %).

Dark matter is thought to be made up of an exotic, as of yet undefined type of elementary particle

It’s worth clarifying several types of hypothetical elementary particle we already had cause to hypothesise (such as the lightest supersymmetric partner), and even some we already know exist (namely neutrinos), are feasible candidates for dark matter, and so there certainly isn’t a consensus that dark matter is something we’ve never even thought of.

The Large Hadron Collider is the only game in town to answer the key questions that have been driving theoretical speculations, from the origin of mass to a possible GUT of all forces, and even the possible existence of extra dimensions

We think mass is due to the Higgs boson; hopefully the LHC will prove its existence in the next few months. (Disproving it will take longer because at first we’ll only prove a 1-Higgs model doesn’t work. In any case, supersymmetric physics needs at least five of them.) Also, it’s normal to hear GUT and TOE used to refer to theories of all non-gravitational forces and all forces respectively.

the Superconducting SuperCollider, a device far larger and more ambitious than the LHC

Indeed; its top proton energy would have been 20 TeV, rather than 7 TeV. That difference would have been crucial.

Current budget woes only make it more likely that we’ll see even less federal support for fundamental science in the next decade—and raising taxes to support big science probably isn’t going to be viewed as a vote-getter in the current presidential race.

Though I share Krauss’s concerns lay Americans may be impossible to persuade of the merit of greater science funding, there is an argument – whether or not it would persuade enough voters – for funding more science that, rather than being antithetical to economic goals, is rooted in them; research shows science research is an especially good investment to grow the economy, e.g. each dollar invested in NASA has returned $8. I heard that from Neil deGrasse Tyson, anyway. He also claims science funding is greater under Republican presidents than under Democrat ones; if that’s true I wonder, should Krauss be rooting for Romney to defeat Obama in November? (In the last few weeks Intrade’s estimate of Obama’s probability of re-election has fallen from 0.57 to 0.53.)

From a purely intellectual perspective and in terms of human progress, perhaps it doesn’t matter where discoveries are made. But… we risk losing both the intellectual and practical benefits that come with remaining a world leader in forefront science throughout this century.

No perhaps about it; unless it can be shown research does Americans much more good than it does Europeans, that both regions are economically well-developed suggests the world will be as healthy one way as the other. It’s the future of research in the developing world that intrigues me.