BOSTON -- Memo to the president and congressional Democrats: Why are you writing off the midterm elections?

Republicans across the country -- Massachusetts to California, Virginia to Texas -- are using Arizona and illegal immigration as an electoral battle cry and have cowed you into playing weak defense.

All the talk is of how the Republicans are going to win big, and your only comeback seems to be, yeah, but wait until 2012, when we clobber you with all these Hispanics. Sounds pretty speculative to me, and I'm Hispanic. It doesn't help if you are up for re-election either.

Sure, some of this is just bad timing. The 2010 vote comes before health care reform and perhaps a revived economy kick in. But as Robert Reich, a Democrat, wrote this week in The Wall Street Journal, the president's legislative successes have been large enough to fuel strong opposition but not big enough to strengthen his support.

And now you're doing it again on immigration. Your successful suit temporarily blocking most of the Arizona law is red meat for the opposition, and wasn't popular with swing voters either. Meanwhile, Univision anchor Jorge Ramos, the most influential Latino in America, says the suit is insufficient and most Latinos agree. Fifty-five percent of Hispanics (and 59 percent of all Americans) in a recent CNN poll gave the president bad marks on his handling of illegal immigration. There goes your November base.

The Republicans are now baiting you deeper into a corner. Last week, Sen. Lindsey Graham -- one of the most pro-immigrant Republicans -- asked for hearings to end birthright citizenship of the children of unauthorized immigrants, and almost every Republican big name piled on. Few actually take the effort seriously, as it would likely require changing the 14th Amendment, but it's all politics.

You are dying the death of a thousand cuts. And all so unnecessarily.

It is time to find your inner Margaret Thatcher. As she taught Ronald Reagan, half the trick in politics is to take command by framing the issues. The policy, morality and politics of illegal immigration are all aligned in your favor, a rare opportunity if only you break out of an outdated mindset about enforcement and go on offense. Even Latinos will support you.

Americans in polls overwhelmingly favor some sort of legalization of the estimated nearly 11 million unauthorized immigrants in the country. Latinos, meanwhile, in polls overwhelmingly support enforcement to stop more from coming, but you have to deliver on legalization, too.

As policy, you have in fact done a good job improving enforcement. Politically, however, you get little credit for it with swing voters because you are afraid to embrace and claim it, and so you can't get enough popular support to force Republicans to move on the second half of the package: legalization.

You recently announced you were sending 1,200 National Guard troops to the border, and then dropped the subject. You are walking the walk, but not talking the talk, almost as if you were ashamed in front of the academics and advocates who hammer that enforcement doesn't work or who never seem to find an enforcement policy they like, for altruistic, ideological or just unrealistic reasons.

These experts are correct in diagnosing what went wrong when haphazard border policies since the 1960s broke back-and-forth migration patterns between the United States and Mexico, but that is now history. Border enforcement is a political imperative in a post 9/11 world, and is working, though a temporary worker program is still needed. Meanwhile, it is unclear whether circular migration can ever be re-established, now that El Norte is home to so many Latinos and other immigrants.

You need to make border enforcement yours, and the only way to do so is to up the ante: more troops, more money. But not in an inside-Washington trade-off for legalization, which is what you have been doing. This turns a negotiating strategy into an end. Then enforcement is no longer yours and the Republicans are playing you again.

No, you need to claim that you are moving on both enforcement and legalization as one. Seize the framing of the issue. And then see how well the Republicans play defense in November.