Minnesota Democrats launched a digital ad campaign last week targeting seven state Senate Republicans who voted against a bill intended to get insulin to patients who need it.

The party would only say the ad buy is "five figures" but will reach more than 150,000 Minnesotans.

Pay attention to the targets: Sens. Jerry Relph of St. Cloud; David Senjem and Carla Nelson, both of Rochester; Warren Limmer of Maple Grove; Karin Housley of the Stillwater area; Paul Anderson of Plymouth; and Dan Hall of Burnsville.

These are all vulnerable Republicans in districts where a Democrat holds at least one of the House seats. (A Senate district comprises two House seats.)

Democrats hope turning up the pressure — combined with an energetic road show by Gov. Tim Walz — will push wavering senators to capitulate on some of Walz's big agenda items, such as a gas tax for roads and a tax on health care providers. Republicans are thus far united in opposition.

Can this kind of effort work at the Legislature?

Danny Hayes of George Washington University and Jennifer Lawless of American University summarized the evidence, finding the public increasingly interested in national, rather than state and local politics.

This means the public might be highly engaged over President Donald Trump's visit to Minnesota Monday, or his latest tweet, but might have trouble working up enough interest in the state budget to call their state Senator.

I asked Brian Evans, the Democrats' new spokesman, about the challenge of getting local people to engage with their Legislature. His response echoed what we've heard from political operatives from both parties in recent years: All politics is national.

This turns on its head the overused mantra of former U.S. House Speaker Tip O'Neill, that all politics is local. But in an era of ideological political parties and an obsessive focus on Washington, local elections are often determined by national winds. Consider 2016, when Republicans took the state Senate on the strength of Trump's results in greater Minnesota. Or 2018, when Democrats took the Minnesota House thanks in large part to suburban disenchantment with Trump.

The DFL ad campaign's Republican targets also have more to worry about than just the Democrats. A vote for a hefty tax increase could lead to a Republican primary challenge in an era when activists — in both parties — demand ideological purity.

Kevin Poindexter, the executive director of the Republican Party of Minnesota, said of the Democrats' gambit, "This is a bunch of hoopla for nothing."

After two special election losses this year, Poindexter said, Democrats are trying to distract voters from Walz's gas tax proposal, along with other policy proposals that he said are duds in the eyes of voters.

The 2020 election will give us some clarity on whether the public favors the policies of Walz or Senate Republicans. But not very much. After all, all politics is national.

J. Patrick Coolican 651-925-5042 Twitter: @jpcoolican patrick.coolican@startribune.com