ST. PAUL — Minnesota Gov. Mark Dayton made $671,724 last year — more than enough to qualify for an income tax hike under his budget proposal, according to tax returns released Tuesday.

The income, mostly from investment gains, is considerably higher than what Dayton earned in 2009, when he reported making $172,472. It’s easily enough to qualify the Democratic governor for an income tax hike under his proposal at the Capitol to increase taxes on the state’s highest earners.

The largest share of Dayton’s 2010 income — $606,919 — came from investment gains. The biggest single gain, $407,665, came from selling 8,431 shares of stock in the Target Corporation, the retailing giant that Dayton’s family founded but no longer controls.

Target Corp. became embroiled in Dayton’s race for governor last year when the company donated $150,000 to a political fund that was backing Dayton’s opponent, Republican Tom Emmer. But Dayton sold the Target stock in early January 2010, months before Target’s donation.

Dayton sold off other stock holdings in January 2010, including large shares of Johnson & Johnson, General Electric, Citigroup and Hutchison Telecommunications.

Dayton campaigned on a vow to raise income taxes on the wealthy in order to eliminate a state budget deficit which now hovers at $5 billion. He has proposed increasing the state tax rate from the current 7.85 percent to 10.95 percent for single filers who make above $85,000 and couples who make more than $150,000.

That’s estimated to raise about $2.4 billion over two years, but Republicans who control the Minnesota Legislature have been united in opposition.

Dayton’s returns show he paid federal taxes of $99,690 and $50,701 in taxes to the state of Minnesota last year. The governor released his tax returns voluntarily, and was not required to do so by law.