Colorado has the seventh-most Democratic state legislature of the 50 states in the United States.

In ranking seventh-most Democratic, Colorado finds itself in the company of states on the east and west coasts. The top eight most-Democratic state legislatures are:

Hawaii — 90.1% Democratic.

Rhode Island — 87.2% Dem.

Massachusetts — 87.1% Dem.

California — 78.8% Dem.

Vermont — 74.4% Dem.

Maryland — 72.3% Dem.

Colorado — 68.2% Dem.

Delaware — 67.4% Dem.

There are two Pacific Ocean states (Hawaii and California), three New England states (Rhode Island, Massachusetts and Vermont), and two middle-Atlantic states (Maryland and Delaware) in this most Democratic state legislatures grouping — along with Colorado.

Colorado may be located high in the Rocky Mountains near the center of the nation, but the political party makeup of its state legislature resembles coastal states, not inland states.

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We studied all 50 state legislatures this spring. We calculated the percentage of Democrats and the percentage of Republicans in a state’s senate and house of representatives. We next averaged those two figures together to get a final figure for that state legislature.

We did not include vacant seats or seats held by third political parties. Also not included was the state of Nebraska, which has a nonpartisan (no political parties) and unicameral (one house) state legislature.

Pennsylvania was excluded from our survey because it is the only state with a state Senate of one party — the Republicans — and a State House of Representatives of a different party — the Democrats. Also excluded from the survey was Alaska, where a Democratic-Republican coalition currently governs the state Senate.

That left 47 states to be studied. We then listed those 47 states from highest percent Democratic to highest percent Republican.

As noted, the eight most Democratic state legislatures favor coastal states plus Colorado. The eight most Republican state legislatures, however, are in the midwest and the south plus Idaho and Wyoming. The top-eight most Republican state legislatures are:

Wyoming — 92.7% Republican.

West Virginia — 90.1% Rep.

North Dakota — 89.4% Rep.

South Dakota — 89.3% Rep.

Arkansas — 82.4% Rep.

Idaho — 82.1% Rep.

Oklahoma — 81.8% Rep.

Kentucky — 80.8% Rep.

These states with Republican-dominated state legislatures are notable for their relatively small or medium-sized populations. Except for West Virginia, they are concentrated in the middle of the country.

The Republicans have a numerical advantage over the Democrats where the numbers of state legislatures controlled are concerned. Republicans have the majority in both houses of 27 of the state legislatures. The Democrats have the majority in both houses of only 20.

Here is the point in our list where control of the state legislature shifts from Democratic to Republican.

Oregon — 58.5% Democratic.

Michigan — 51.8% Dem.

Virginia — 51.8% Dem.

Minnesota — 51.5% Dem.

Arizona — 51.7% Republican.

New Hampshire — 54.6% Rep.

Georgia — 57.7% Rep.

North Carolina — 60.0% Rep.

As expected, states with a legislative chamber, or two, that might shift from one political party to the other can be found on this list.

According to political analyst Louis Jacobson, chief correspondent for PolitiFact, both the Arizona state Senate and the Arizona State House of Representatives are in position to possibly change from Republican to Democratic. Another chamber that could shift Republican to Democratic is the New Hampshire House.

On the other hand, legislative chambers that might go Democratic to Republican are the Michigan House, the Minnesota House and the Pennsylvania House.

This study suggests state legislative chambers rarely change from one political party to the other.

Thus Wyoming is likely to have a Republic legislature for the foreseeable future, just as Massachusetts will likely have a Democratic legislature for the near future. There are a total of 98 state senates plus state houses of representatives in this study, and Jacobson could only find the six chambers listed above that could be rated as toss-ups.

This suggests the normal pattern in most states is for one political party to control both houses of the state legislature for long periods of time.

One of the most important facts about state legislatures is that, in every state but three in spring 2024, one of the major political parties controlled both houses of the state legislature. The three exceptions were Nebraska (non-partisan), Pennsylvania (one house Democratic, one house Republican), and Alaska (two-party rule in state Senate).

That means 47 of 50 states have a legislature where both houses are controlled by the same political party.

The overall pattern is this: Democrats have two major areas of state legislative control. One is on the north east coast of the Atlantic Ocean from Virginia to Maine, with New Hampshire as the only Republican exception. The other major area of Democratic control of state legislatures is on the west coast and is comprised of the states of California, Oregon, Washington and Nevada.

With only five exceptions, the Republicans control both houses of the state legislatures in all the rest of the country. From the south through the Midwest to the great plains to the mountain west, the Republicans rule two chambers except in Michigan, Illinois, Minnesota, Colorado and New Mexico — all five of which have both houses controlled by Democrats.

Longtime residents of Colorado may remember that, 40 years ago, when Ronald Reagan was president of the United States, both houses of the Colorado legislature were dominated by the Republican Party. The last four decades have seen the Colorado state legislature switch from solidly majority Republican in the 1980s to the seventh-most Democratic state legislature in 2024.

This study of political party patterns in state legislatures indicates the Colorado legislature is going to be Democratic for at least the next several years.

Tom Cronin and Bob Loevy are columnists who write about Colorado and national politics.