Chuck Grassley, the former Republican chairman of the Senate Finance Committee who has represented Iowa in the upper chamber of Congress for the better part of the past three decades, is getting a little crochety these days. Take a look, for instance, at a report on the Associated Press wires today.

Republican Sen. Charles Grassley says Democrat Barack Obama was not acting like a proper senator when he called on Iowans to lobby Grassley to change his position on the Iraq War.

The Iowa senator, speaking to reporters during a conference call on Wednesday, bristled at Obama's decision to call him out on his home turf.

"Let's say -- pretty much -- that it's not senatorial and if you can't be senatorial, how can you be presidential?" Grassley said.

At a campaign event in Waterloo on Sunday, Obama told the crowd, "We intend to force our colleagues in the Senate and House to take vote after vote until we overcome (the president's) veto. I'm not going to name names, but there's at least one senator in Iowa who could be helpful."

That was a thinly veiled reference to Grassley, who has stood by President Bush's Iraq policy. Sen. Tom Harkin, D-Iowa, is a vocal critic of the war.

If there were ever a portrait of someone who has spent too long on Capitol Hill, this might be it. Grassley apparently believes that he owns the Hawkeye state, that no one -- particularly not another Senator -- has the right to organize a grassroots lobbying effort among his constituents.

Of course Grassley is wrong. But his position is understandable if you take a moment to think about the position he is in, particularly given that he hasn't faced a real electoral challenge in years. The last time he stood for reelection, in 2004, Grassley faced only nominal opposition from the Democrats -- he outspent his Democratic challenger by a $6.4 million to $135,000 margin, for instance -- and was able to cruise to an easy 42-point victory, carrying each county in the state. During his previous reelection campaign in 1998, Grassley outspent his Democratic challenger by a slightly narrower $2.7 to $165,000 margin and won by 37 points. In fact, you have to go back to Grassley's initial run for the Senate against then-incumbent Democrat John Culver to see the Democrats offering him a truly active challenge. No wonder he believes Democrats shouldn't be questioning his actions.

Yet it is not only a sense of entitlement fostered by a lack of Democratic opposition that led Grassley to get up in arms about Obama's call to action in Iowa. While Grassley may be out of touch with Iowans, he is not so out of touch that he doesn't know the ground is shifting under him (even if this has not led him to change his voting pattern). In 2006, Iowa swung noticeably towards the Democrats, with the Dems winning the governorship, picking up two congressional seats and gaining control over both the state House and the state Senate -- the first time the Democrats in the state have controlled the Governor's mansion and both chambers of the state legislature since Lyndon Johnson was President. This trend could spell real trouble for Grassley, a stalwart Republican who backed President Bush's position 87 percent of the time and stood with his fellow Republicans on party-line votes 93 percent of the time in 2006 (both numbers according to CQ).

As is fairly apparent, Grassley is vulnerable -- and he knows it. This is why he is so offended that a Democrat would come into his state, expose his knee-jerk conservatism and call his constituents into action to lobby him. So kudos to Obama for calling Grassley out. He, and other Democrats for that matter, should keep this up, going to marginal districts and states that have elected to Congress Republicans who are unwilling to rethink their blind fealty to President Bush over the Iraq War. And if these Republicans don't change their ways, the Democrats should send them a strong challenger the next time they're up for reelection (in Grassley's case, 2010).