There are two ways to assess Mitt Romney's decision to attack traditional Medicare and talk up the merits of partial privatization:

Either he has a lot of guts, or he's stark-raving nuts.

I had long been under the impression that Romney would spend the campaign inveighing against the economy, hewing to a mantra of jobs-jobs-jobs. But clearly he and his team calculated that the economy was not sufficiently miserable to propel him into office, and that his conservative base was still not sufficiently stoked about him. Enter Paul Ryan, who wants to phase out the Medicare guarantee, move future seniors into a voucher program, and compel many of those seniors to pay more money out of pocket.

The conservative base loves Ryan. The conservative think-tank intelligentsia loves Ryan's plan to abolish the insurance guarantee. But the GOP ticket is flirting with political suicide.

The polls are virtually unanimous about this. For instance, the Kaiser Family Foundation said in a February survey that 70 percent of Americans (and 71 percent of swing-voting independents) want to keep Medicare as it is; only 25 percent (and 24 percent of swing voters) support partial privatization. And last year, after the House passed Ryan's budget plan, the ABC News-Washington Post poll said that 65 percent opposed the idea of a voucher program, and that opposition swelled to 85 percent when people were told the vouchers wouldn't cover all medical care.

No wonder a lot of Republicans are terrified. They know from long experience that taking on Medicare is a political loser. Republicans running for Congress signaled last week that they intended to ignore the Medicare issue and focus solely on the economy. Some are going a step further. Denny Rehberg, the GOP senatorial candidate in Montana, has aired an ad attacking Ryan's budget plan. Rehberg had opposed it in the House, and he wanted voters to know. The narrator intones: "Rehberg refused to support a Republican budget plan that could harm the Medicare programs so many of Montana's seniors rely on."

This is Montana we're talking about. Not a hotbed of socialism.

Rehberg undoubtedly remembers what happened last year in a special House election in Upstate New York, in a rural-suburban district that had been solidly Republican since 1857. Republican Jane Corwin was expected to win in a walk - until the House Republicans passed the Ryan budget plan. Democrat Kathy Hochul promptly went to war on Ryan's privatization blueprint. At first, Corwin tried to defend it; then she said she wasn't "married to it." Hochul won by four points.

And look at Arizona. Two months ago, there was a special House election to fill the seat vacated by Democrat Gabrielle Giffords. The district leans Republican (Giffords won narrowly in 2010), and President Obama polls badly there. But the Democratic candidate won the June contest by six points after he highlighted his GOP opponent's long history of dissing traditional Medicare.

Translation: Even though a lot of voters oppose "government" in the abstract, they still want its benefits. Woe to the politicians who would curb or cancel those benefits. As Democratic pollster Stan Greenberg noted in a recent memo, "Seniors are particularly receptive to attacks on the Ryan budget and are willing to punish Republicans for touching Medicare."

Frankly, I don't get it: Why would Romney risk alienating seniors? They vote heavily; they're potentially pivotal in Pennsylvania, Florida, Ohio, and Virginia; and they were cool to Obama even in 2008. Romney polls better with seniors than with any other age bracket. He can ill afford to lose any of them. Granted, Ryan's Medicare plan (which Romney sort of endorses but which he now owns anyway) would exempt current seniors. But current seniors may well be wary of "reforms" that would adversely affect their adult children, the seniors of tomorrow.

Romney-Ryan is nonetheless bullish on Medicare; it thinks it can neutralize the issue by going on offense and spotlighting the $716 billion that Obama took from Medicare to help fund the health-reform law. This strategy worked in Nevada in September, when a Republican cruised to victory in a special House election after telling senior voters that Obama was cutting their medical care. Which is why Romney surrogate John Sununu went on TV last week to claim that Obama had "gutted Medicare."

Three problems with that claim:

1. It's factually incorrect. The health-reform law will slow the rate of growth of payments to Medicare providers by roughly $700 billion over 10 years. Seniors on Medicare will not lose any benefits. In fact, they'll gain benefits - because, under the reform law, some of those billions are earmarked for seniors' prescription drugs and various preventive services.

2. It turns out that, in one version of Ryan's plan, the running mate envisioned taking the same amount of money out of Medicare. (Oops!) Romney has been forced to finesse this inconvenient fact by pledging to put the money back into Medicare. Which kind of muddies his attack line against Obama.

3. Voters may resist the notion that Obama is a threat to Medicare and that Romney is its protector. That notion runs counter to the general perception of the two parties dating back to the dawn of Medicare in 1965. Democrats are widely seen as "the party of government." In current parlance, that's their "brand." In debates over safety-net issues such as Medicare, they tend to have the upper hand.

In other words, Romney has chosen to fight on Democratic turf. Another Kaiser Family Foundation poll, conducted last month, told the tale. When respondents were asked which presidential candidate could best be trusted "on handling Medicare," Obama was favored by 11 points. No wonder the White House is ecstatic about Ryan's ascent. No wonder so many Republicans equate the issue with TNT.

Which reminds me of a story. In April 2011, right after the House GOP said yes to Ryan's Medicare plan, presidential candidate Tim Pawlenty (now a Romney surrogate) was asked for comment. Tiptoeing around the TNT, he said he liked Ryan's plan "directionally." The reporter persisted: "Do you support the Medicare cuts in his plan?"

Pawlenty's full reply: "Anybody else have a question besides this guy?"

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