When Arizona was admitted to statehood in 1912, Henry Fountain Ashurst became the new state’s first U.S. senator, a position he held until he lost the 1940 Democratic primary.

Mark Shields

Mark Shields

Ashurst’s thoughts after his defeat remain timeless: “The welfare of the United States, and the happiness of our people, does not hang on the presence of Henry Fountain Ashurst in the Senate. When that realization first came to me, I was overwhelmed by the horror of it, but now it is a source of infinite comfort.”

Given the anger of the nation’s voters captured in the most recent NBC NewsWall Street Journal poll, a lot of incumbent office-holders facing the unhappy electorate in November — especially Democrats — would be wise to reflect on Ashurst’s words. Voters, in the judgment of Democratic pollster Peter D. Hart, who conducts the NBC-Journal survey with Republican pollster Bill McInturff, are “disgusted and unhappy.”

True, not all of the numbers are bad for Democrats. When voters were asked: “What is your preference for the outcome of this year’s congressional elections — a Congress controlled by Republicans or a Congress controlled by Democrats,” a Democratic-controlled Congress was preferred 45 percent to 42 percent.

But a real problem looms for the Democrats a little more than seven months before Election Day: When voters were asked to rate how interested they were in November’s elections on a scale from one (not at all interested) to 10 (very interested), just more than half — 53 percent of respondents — expressed great interest in the elections by answering either nine or 10.

Here’s the important political news: 67 percent of Republicans expressed great interest in the upcoming congressional elections, while just 46 percent of Democrats said they were equally excited about November. Those numbers represent an almost total reversal of the interest factor from 2006 and 2008, when all the excitement was on the Democrats’ side.

High interest in an election is a strong predictor of probability of voting in that election. So based on voters now expressing high interest in the 2010 elections, the Democrats’ 45-42 preference among all those polled turns instead, among those most likely to vote, into a 52 percent-39 percent Republican landslide.

The Democrats’ acutely controversial and generally unpopular health-care reform legislation could surprisingly offer the best possible instrument for increasing Democratic voters’ interest and enthusiasm in the 2010 elections. While a plurality of voters think “President (Barack) Obama’s health-care plan” is a “bad idea,” when voters were asked, “Do you think it would be better to pass Barack Obama’s health-care plan and make its changes to the health-care system or to not pass this plan and keep the current health-care system,” they split down the middle. Forty-six percent believes it’s better to pass the Obama plan with its changes, and 45 percent opposes passing the plan and prefers maintaining the status quo.

But as Hart points out, Democratic voters — by an overwhelming 64 percent to 16 percent — endorse the Obama health-care plan. Thus, to energize and engage a basically demoralized Democratic base, congressional Democrats would be wise to vote for the Obama plan. If health care passes, then critics could still accuse the Democratic Congress of being too liberal, but nobody could legitimately charge that this has been a “do-nothing” Congress.

So, for Democrats on Capitol Hill facing a difficult re-election, voting for Obama’s health plan, while certainly controversial and not without risks, could be their best chance of awakening a lethargic Democratic electorate and turning them on and turning them out at the polls on Election Day.

Mark Shields is one of the most widely recognized political commentators in the United States. The former Washington Post editorial columnist appears regularly on CNN, on public television and on radio. Click here to contact him.