Apart from Reagan, unemployment increased under every Republican presidents and dropped under every Democrat presidents for about 100 years.

•    Democrat        Republican
• -0.218% Avg.     0.364% Avg.

US Department of Labor Statistics provides this information. Average unemployment is 0.9% better for each Democrat presidential term and about 1.5% worse for each Republican presidential term. 

•    President               Change
• Truman (D)       -0.15% Avg. Per Year
• Eisenhower (R)   0.357% Avg. Per Year
• Kennedy (D)      0.066% Avg. Per Year
• Johnson (D)       -0.42% Avg. Per Year
• Nixon (R)           0.333% Avg. Per Year
• Ford (R)             0.933% Avg. Per Year
• Carter (D)          -0.15% Avg. Per Year
• Regan (R)            -0.2% Avg. Per Year
• Bush I (R)              0.5% Avg. Per Year
• Clinton (D)      -0.438% Avg. Per Year
• Bush II (R)         0.263% Avg. Per Year

The last depression occurred during the Republican presidencies of Calvin Coolidge and Herbert Hoover. We are in another depression. 

Why?

Three reasons: education, immigration, and banking.

First: education.

Apart from Reagan, every Republican president has reduced education funding. The decline corresponds with the War on Drugs that began in the 1920s with prohibition.

We establish that (a) the true rate is substantially lower than widely used measures; (b) it peaked in the early 1970s; (c) majority/minority differentials are substantial and have not converged for 35 years; (d) lower post-1970 rates are not solely due to increasing immigrant and minority populations; (e) our findings explain part of the slowdown in college attendance and rising college wage premiums; and (f) widening graduation differentials by gender help explain increasing male-female college attendance gaps.

The War on Drugs, which spent $1 trillion while education funds were being reduced.

Declining education is linked with unemployment because the average bachelors degree doubles income and reduces unemployment risk by half. Bachelors degree reduces incarceration risk by 95% by providing steady income.

Education is also known as human-capitol development.

Second: immigration.

Half of wealth of the US exists as real estate, and wealth increases while the population increases. That is basis for the whole "Keynesian Economics" thing.

Apart from Reagan, every Republican president has blocked immigration to "protect American jobs for Americans" despite the fact that immigrants dominate farm labor where almost no US citizens are employed.

US citizen birth rate is 2.1, which cannot sustain growth due to deaths before workforce entry. Our economic growth depends on immigration.

Millions of undocumented immigrants left the US starting in 2007 creating hundreds of thousands of abandoned dwellings by 2009 that collapse the real estate, construction, and mortgage industries.

This population decline occurred after the revised Patriot Act that legalized state and local auto-theft from immigrants that can't get drivers licenses because employers refuse to pay the $1,500 documentation fee for foreign workers.

Bank failures and unemployment peaked in 2010 due to mortgage payment failures resulting from dwelling abandonment and used car auctions.

The Great Depression occurred during Mexican Repatriation, which is the last time the economy collapsed at the same time the population declined after Mexicans were outlawed the first time.

Third: bank policies.

Apart from Clinton, every Democrat president has maintained financial protections created during the Great Depression.

The Glass-Steagall Act of 1933 created 3 different finance industries by prohibiting commingling of funds between banking, stock exchange, and insurance funds. This is the reason the Great Depression was not repeated from 1947 until 2006.

The Gram-Leachy-Bliley of 1999 legalized the co-mingling of funds between bank, security, and insurance industries. Banks are prohibited from participating in sub-prime mortgage lending, but this makes that practice legal in 2003, and this undermines the authority of Federal Deposit Insurance Corporation.

The Commodity Futures Modernization Act of 2000 allows mortgages to be bundled and sold as stock on the New York Stock Exchange. This allows banks to begin purchasing sub-prime mortgage "derivatives" in 2003, and this undermines the trust of Federal Deposit Insurance Corporation.

The Responsible Lending Act of 2003 allows lenders to create sub-prime mortgages. This also allows banks to grow enormous by crossing state and international borders, and this quickly undermines the capacity of Federal Deposit Insurance Corporation. As much as 5 million unaffordable loans are created annually from 2003 until 2009.

These laws create financial dynamite by allowing banks to rapidly inflate real estate value by pumping savings through the New York Stock Exchange to produce over $1 trillion of mortgages for borrowers that can't pay. This works as long as the population is increasing.

The Patriot Act lit the fuse on the dynamite by collapsing the undocumented immigrant population from 2007 through 2009.

George Bush authorized border protections that were applied to California and Arizona where economic collapse has been the worst. 

Texas avoided the worst impact of the economic by encouraging immigration.