(Updated: See below.)
The Wall Street Journal's editorial board (which for decades has been completely separate from the news side, and noted for its extremely conservative point of view -- not that there's anything wrong with that) predictably has its own take on spending growth under Obama.
Just as predictably, one has to wade through a fair amount of spin. For example, it's implied that Obama's stimulus bill involved $800 billion of spending in fiscal 2009. In fact, the bill authorized only a bit over $500 billion in actual spending (the rest was tax cuts), and the great bulk of that money was not spent until subsequent fiscal years.
But overlooking all that, let's be generous and assume the editorial is actually right about the following: "To anyone who really knows the numbers, Mr. Obama's spending has increased by closer to 5% a year." In context, "closer to" implies "not quite," but let's use the 5% figure.
As Talking Points Memo points out, even using this number, spending growth under Obama is still substantially lower than under George W. Bush (all rates in percent per year):
7.3 GW Bush (first term)
8.1 GW Bush (second term)
5.0 Obama (per WSJ editorial board's "closer to" figure)
Update: Because of a dumb editing error on my part -- meaning I typed something in the wrong place -- this post previously labeled the second line above as limited to the first three years of Bush's second term. In fact, the figures (taken from the TPM linked to above) are for the entire second term. Mea culpa.
These figures are for nominal spending growth, and one might quite reasonably object that it would be fairer to compare growth rates adjusted for inflation. (In fact, I think failure to account for inflation makes TPM's numbers for Reagan and George H.W. Bush misleadingly high, which is why I'm not quoting them here.)
Much less reasonably, one might call for not counting the sharp spending increase in Bush's last year, since it was intended to address an economic crisis. (That crisis was attributable to shredding Depression-era protections that had prevented any similar financial meltdowns in intervening years, but that's a separate matter.) Of course, Obama's stimulus was also intended to address an economic crisis.
But OK, let's adjust for inflation, and let's ignore the final year of Bush's presidency, when spending shot sharply upward, but let's not give any similar break for Obama's stimulus. Here's what we get:
4.9 GW Bush (first term)
3.4 GW Bush (first three years of second term)
2.5 Obama (based on WSJ editorial board number)
The bottom line: Even using the WSJ editorial board's figure for Obama's spending growth rate, and bending over backwards to understate spending growth under Bush, it's hard to justify the claim that spending has exploded under Obama.