The media narrative from last night’s primaries has been …. predictable. If 2010 could be described as Tea Party Wars: A New Hope, then last night was supposedly The Establishment Strikes Back. It’s not that simple, but it’s not entirely false either. One corroborating piece of evidence comes from a new CBS News poll showing the Tea Party losing support, even among Republicans:

The tea party was an important factor in the 2010 elections, but its support may be waning, according to a new CBS News poll. Today, just 15 percent of Americans say they are supporters of the tea party movement – the lowest since CBS News began asking about the tea party in February 2010. The tea party reached its highest level of support (31 percent) in November 2010, soon after the midterm elections.

The movement may be losing some of its core constituency — Republicans. 32 percent of self-identified Republicans now consider themselves supporters of the tea party – down 10 points from February and a decline of 23 points from July 2010, the summer before the Republican Party took control of the House of Representatives. The percentage of Republicans who identify as tea party supporters is now among the lowest in CBS News Polls.

That does tend to fit in with last night’s results. Established candidates, even those with not-so-strong ties to The Establishment, fared better than grassroots favorites, and not just in Kentucky — and not just among Republicans:

Senate Minority Leader Mitch McConnell defeated his GOP challenger in Kentucky by 25 percentage points, a high-profile but low-suspense race on a critical primary day when voters cast ballots in six states. In Georgia, a Senate Republican primary headed to a runoff with the two candidates favored by GOP establishment leaders. And in Oregon, pediatric neurosurgeon Monica Wehby fended off a more conservative challenger in her Republican primary.

Pennsylvania Democrats, meanwhile, picked businessman Tom Wolf, who poured $10 million of his own money into the race, as their nominee against Gov. Tom Corbett, one of the most vulnerable Republicans in the country. Also in the Keystone State, Chelsea Clinton’s mother-in-law, Marjorie Margolies, lost a bid to reclaim her old House seat, despite some assistance from Bill and Hillary Clinton.

After a year of threats from conservative outside groups, no GOP incumbents lost Tuesday. Idaho Rep. Mike Simpson beat back a tea partier supported by groups such as Club for Growth, with help from the business lobby and Mitt Romney. National Republican Congressional Committee Chairman Greg Walden, targeted in Oregon by a national campaign called Primary My Congressman, received triple the support of his opponent with more than half the votes in. And House Transportation and Infrastructure Committee Chairman Bill Shuster prevailed over his challenger in Pennsylvania by 18 points.

Republican leaders have maneuvered to nominate candidates who they hope can avoid the kinds of foot-in-mouth mistakes that cost them winnable races last cycle in red states like Missouri and Indiana.

We will hear plenty from the media about the Tea Party losing ground, and that may have played into last night’s primaries, but it doesn’t tell the whole story either. Incumbents who won last night did so by embracing the Tea Party agenda, at least in part. The movement has impacted the so-called establishment by shifting it to the fiscal-conservative and smaller-government Right. Incumbents are no longer getting ambushed by treating re-election efforts as walkovers, mostly because they have spent the last couple of years listening to their constituencies rather than ignoring them.

That doesn’t mean that they won’t have problems. The two runoff candidates in Georgia for the open US Senate seat are both good candidates, but they may do more damage yet to each other before one emerges as the nominee. That candidate will start off behind Michelle Nunn in general-election campaigning, and they will need to work hard to get the grassroots engaged. Mitch McConnell scored a big victory over Matt Bevin, but it was the weakest performance by an incumbent Senator from Kentucky in 75 years.  Democrats outdrew Republicans to the polls in yesterday’s Kentucky primary by more than 48,000 voters, and Alison Lundergan Grimes got nearly 94,000 more votes than did McConnell.

In other words, even though the Tea Party didn’t “win” nominations in last night’s primaries, the grassroots will more critical than ever for the GOP in these key races. No one has lost anything yet — and no one’s won anything, either.