Barack Obama has received considerable criticism for changing his positions on public financing (will now not use it in his campaign), and on FISA (supports the bill passed by the House). A few disappointed supporters have said he's therefore no different from John McCain, who changed his position on Bush's tax cuts (McCain now supports them), etc.
I think this misses the point, which is: what counts most is not whether a candidate changes positions, but whether the change is for the better or the worse. Let's look at the candidates and the issues:
Obama on public financing: I frankly never liked public financing of Presidential campaigns in the first place. Designed to prevent wealthy donors from dominating an election, public financing laws also get in the way of all Americans contributing to campaigns. Further, in the Bush/Kerry election of 2004, loopholes allowed millions of dollars to be spent on ads that swiftboated Kerry. And, worst of all, public financing gives the government too much power. It is illogical and dangerous to democracy to have the government that is up for election also determine who gets public financing for the election, and how much.
This year, Obama would have received $84.5 million from the US Treasury for his campaign, would have been unable to accept any private contributions, and would have been prohibited from spending more than the $84.5 million. Given that Obama took in $95 million in private contributions in just March and April, and more than 90% of his donations were under $100 (according to Obama's communications director, as reported in The New York Times), Obama's acceptance of public financing would not only have made no financial sense, but would have been a slap in the face of democracy. His opting out - even though he had previously said he wanted to work with public financing - was the right thing to do.
Obama on FISA: The Bush's administration's wiretaps after September 2001 were a direct violation of FISA (Foreign Intelligence Surveillance Act) provisions that a special court has to approve or warrant the wiretaps (Bush's wiretaps were not approved by the FISA court). The FISA Amendments Act of 2008 is intended, in part, to make sure that does not happen again. A sticking point is what to do about telecom companies - AT&T, Verizon, etc - which permitted the illegal wiretaps. Many Republicans want to give them immunity from invasion of privacy suits. Many Democrats do not.
Back in February, Obama said he would not support a FISA Amendment Act which did not hold the telecom companies accountable. Last week, Obama said he would support the FISA Amendments Act which passed in the House, even though that Act does provide immunity for the telecom companies.
Here is why Obama's change of position makes sense: 1. We need a strong statement from Congress that FISA must be respected from now on. Delaying or defeating the FISA Amendments Act would work against that. 2. According to Keith Olbermann quoting John Dean on Countdown the other night, the immunity in the Act pertains only to civil suits - the telecom companies could still be held liable for criminal proceedings (as would the Bush administration).
McCain on Bush tax cuts: As just one example of the kinds of changes in position McCain has been offering, consider that he correctly denounced Bush's tax cuts for the very wealthy, and now endorses Bush's taxes. I can see nothing positive or useful in McCain's reversal of positions - unless we agree with Bush that the ultra-rich were paying too high a tax.
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In sum, then: Not all modifications of positions are equal. In the case of Obama's change of positions on public financing, and on FISA, they make sense. We might reasonably have wanted Obama to have come to these positions sooner, but by far the more important point is that he has the right, or best possible position, now. If this is in part a result of being attuned to the political climate, that's not necessarily bad - part of being a successful public servant is being flexible, and attuned to changing circumstances.
In the case of McCain, no circumstances regarding Bush's tax cuts have changed - it was wrong to punish the less wealthy then, and it's wrong now.