Election year 2012 is shaping up as a lively contest of ideas at both national and state levels.

President Obama probably has nothing to worry about in Vermont. In 2008 his margin of victory in Vermont was as wide as anywhere in the nation, and though liberals have suffered disappointments during his term, the idea that Mitt Romney might supplant Obama in the hearts and minds of Vermonters verges on laughable.

Obama’s strength in Vermont ought to serve Gov. Peter Shumlin well. Though he hasn’t said as much explicitly, Shumlin will be seeking his second two-year term. The last time a Vermont governor was booted out of office after only one term was 50 years ago, when Philip Hoff defeated F. Ray Keyser. One of the factors in Hoff’s favor was the calendar: 1962 was not a presidential election year, so turnout was relatively low. Because Republicans were a majority party at the time, low turnout favored the Democrats, who had mapped out a strategy to use their growing strength to pull off a historic upset.

With Obama bringing Democrats to the polls in large numbers this year, Randy Brock, the Franklin County senator who will be Shumlin’s Republican opponent, cannot count on a similar advantage. Indeed, a scan of the history since Hoff’s stunning victory in 1962 suggests that voters will be inclined to give Shumlin a second term.

Voters in the last 50 years have alternated regularly between Republicans and Democrats. Hoff initiated a period of rapid and dramatic change, followed by the four-year tenure of Deane Davis, a traditional Republican, who consolidated major changes initiated by Hoff but retreated from Hoff’s activist rhetoric.

Davis was followed by Tom Salmon, who showed that Hoff’s Democratic victory was not a fluke, followed by eight years of Republican Richard Snelling. Snelling emphasized sound government, not experimentation. He was followed by the six-year tenure of Madeleine Kunin, a pioneer for women in public service who ushered in a significant change in tone and emphasis in Montpelier.

Voters returned Snelling to office after Kunin’s three terms, but Snelling died in the first year of his new term, and Howard Dean took over for more than 10 years. Dean maintained Snelling’s fiscal conservatism, but he initiated a period of activist government, pursuing health care reform and promoting major land conservation efforts.

Voters swung back in the other direction after Dean’s tenure, electing James Douglas for four terms of Snelling-like caution, integrity and restraint.

On the heels of Douglas comes Shumlin. His pioneering health care initiative is just getting off the ground, and voters are likely to give him a chance to make it work. Brock’s response to Shumlin’s initiatives is to say, more or less, “I’m not so sure about that.” After electing Shumlin once, it’s not clear that voters will be ready to reject their own choice for change.

Other battles are shaping up down on the ticket. Wendy Wilton, Rutland City treasurer, has announced she will challenge Beth Pearce, who was appointed to replace Treasurer Jeb Spaulding when Spaulding joined the Shumlin administration. Wilton has been a good treasurer for Rutland City. Pearce has been an accomplished deputy treasurer and now treasurer.

The Democratic primary for attorney general promises to be a sharply contested race, with Chittenden County State’s Attorney T.J. Donovan challenging incumbent William Sorrell. Sorrell may be vulnerable because he has been in office for a long time and has suffered several notable reversals in court. Donovan has mounted an aggressive bid to unseat him.

In the auditor’s race, incumbent Tom Salmon announced Friday he would not reek re-election. Democrat Doug Hoffer, who lost to Salmon two years ago, has hinted he may enter the race.

Voters are likely to be energized this year because of the presidential race. For that reason, Democrats in Vermont ought to be smiling. But these are unpredictable times. Elections are half a year away.