Mitt Romney handily won the Nevada GOP presidential caucuses on Saturday, taking 50 percent of the votes and all but three counties. However, only about 33,000 people caucused — 10,000 fewer than four years ago, and about half the number state Republicans were predicting. The disappointing turnout follows underwhelming Republican participation in Iowa, New Hampshire, and especially Florida. Aren't Republican voters supposed to be "fired up to dispose of the Obama presidency?" asks Ed Rogers at The Washington Post. Maybe not. Here, four explanations for the GOP's lagging turnout:

1. GOP voters are disappointed with the candidates
Democrats voted in their primaries and caucuses in record numbers in 2008 because they had "two candidates with fervent support," says Carter Eskew at The Washington Post. This year's shrinking GOP numbers "support the general consensus that the field is weak," and Republicans are reacting with a "curious" indifference. "There's a lot of people not satisfied with any of the candidates out there," said one of those candidates, Rep. Ron Paul (R-Texas), on Sunday. "And that's why in many ways we're seeing a lower turnout right now."

2. Actually, it's just Romney who fails to excite voters
"When Newt Gingrich surged in South Carolina, he brought along massive gains in turnout — record turnout, in fact," says Mathew D. Staver in The Washington Times. When Romney "surged" in Florida, turnout dropped 12 percent. Clearly, the real problem isn't the GOP field, it's Romney. In his big Nevada win, Romney trounced his opponents with... just under 16,500 votes, says Dean Esmay at Dean's World. "Romney's Achilles heel continues to be voter enthusiasm," and it will be a problem when "dispirited conservatives" stay home in November.

3. Negative campaigning is turning off voters
Sure, Romney isn't a particularly strong frontrunner, says Mike Smithson in Britain's The Telegraph. But this is more about "the impact of negative campaigning." After a brutal, exceedingly expensive slash-and-burn ad blitz between Romney and Gingrich in Florida, turnout plummeted. "There have been a number of academic studies that suggest that while negative campaigning can motivate the base of support it can also alienate other voters, thus reducing voter turnout."

4. Saturday caucuses are inconvenient
The average GOP voter ardently wants Obama to be a one-term president, but doesn't much care which candidate replaces him, say Nevada Republicans — at least not enough to give up a Saturday. "Republicans are excited to get a new president in," Nevada GOP official David Buell tells the Las Vegas Sun. "Are they excited about going to a caucus? Apparently not."