The Miami Herald has the story:

U.S. Rep. Lincoln Diaz-Balart, a passionate defender and architect of legislation to strengthen the U.S. embargo against Cuba, is expected to announce Thursday he won't seek reelection to Congress.

With this retirement, more than 1-in-10 Republicans in the House of Representatives will not run for reelection this year -- 10.1 percent, to be precise. This kind of exodus does not occur when a party genuinely believes that it has the shot of retaking the House.

Some might try to play off this news by trying to say that the Republicans leaving the House are not endangered members, but rather that they are leaving seats that are sure to stay in the hands of the GOP. There's an extent to which this is true -- but it's far from the overall rule. Lincoln Diaz-Balart represents a district that came close to splitting its presidential vote evenly in 2008, a district John McCain carried by a narrow 51 percent to 49 percent margin. The Michigan district Republican Congressman Vern Ehlers announced yesterday he would be vacating was even more closely contested in 2008, splitting its vote 49 percent to 49 percent between McCain and Barack Obama.

So regardless of the spin you hear out of the Beltway today, do realize that there is simply no way in which this is good news for the Republicans. It's just not. Instead, it's an indication that a great number of House Republicans -- those on the front lines, those actually seeing the internal polling -- don't believe their party has a legitimate shot at retaking the House in 2010.